| Aspect | Waist | Hips |
|---|---|---|
| Definition | Narrowest part of the torso, typically located above the navel and below the ribcage. | Widest part of the pelvic region, measured around the fullest area of the buttocks. |
| Anatomical Location | Sits between the lower ribs and the iliac crest of the pelvis, near the L3 vertebra. | Overlies the greater trochanter of the femur and the gluteal muscles, at the level of the pubic symphysis. |
| Primary Function | Provides flexibility for trunk bending and twisting, housing digestive organs. | Supports body weight during sitting, walking, and running, anchoring lower limb muscles. |
| Bony Structure | No direct bony landmark; defined by soft tissue and muscle compression. | Formed by the ilium, ischium, and pubis bones of the pelvis, plus femoral heads. |
| Muscle Composition | Comprises the rectus abdominis, obliques, and transversus abdominis muscles. | Comprises the gluteus maximus, medius, and minimus, plus hip flexors and rotators. |
| Fat Distribution | Stores visceral fat around internal organs, linked to metabolic disease risk. | Stores subcutaneous fat beneath the skin, associated with lower cardiovascular risk. |
| Measurement Method | Measured at the narrowest point, usually midway between the lowest rib and the top of the hip bone. | Measured at the widest circumference, typically around the buttocks, with feet together. |
| Standard Tape Placement | Tape is placed horizontally at the level of the navel, snug but not compressing skin. | Tape is placed horizontally at the fullest part of the buttocks, parallel to the floor. |
| Average Female Size | Typical female waist circumference ranges from 28 to 34 inches (71–86 cm). | Typical female hip circumference ranges from 36 to 42 inches (91–107 cm). |
| Average Male Size | Typical male waist circumference ranges from 32 to 40 inches (81–102 cm). | Typical male hip circumference ranges from 36 to 44 inches (91–112 cm). |
| Waist-to-Hip Ratio | Waist measurement is the numerator in the WHR calculation, used for health screening. | Hip measurement is the denominator in WHR; higher hip values lower the ratio. |
| Health Risk Indicator | Waist above 35 inches (female) or 40 inches (male) signals increased metabolic syndrome risk. | Hip size alone is not a risk marker; larger hips relative to waist indicate lower risk. |
| Bone Density Influence | Waist size is minimally affected by skeletal width; changes reflect fat and muscle mass. | Hip width strongly correlates with pelvic bone structure, which varies by sex and genetics. |
| Hormonal Influence | Cortisol promotes visceral fat storage in the waist during chronic stress. | Estrogen promotes subcutaneous fat deposition in the hips and thighs in females. |
| Age-Related Changes | Waist tends to increase with age due to muscle loss and visceral fat gain. | Hips may narrow after menopause as estrogen declines and fat redistributes to the abdomen. |
| Exercise Response | Waist reduces with core exercises and overall fat loss; spot reduction is ineffective. | Hip size changes minimally with exercise; gluteal training can increase muscle mass slightly. |
| Posture Impact | Anterior pelvic tilt can make the waist appear shorter and wider. | Posterior pelvic tilt can flatten the hips and reduce their apparent circumference. |
| Clothing Fit | Waist measurement determines pant waistband size and dress bodice fit. | Hip measurement determines skirt, pant, and trouser seat and thigh fit. |
| Body Shape Classification | Waist relative to hips defines apple (high waist) versus hourglass (narrow waist) shapes. | Hips relative to shoulders define pear (wide hips) versus rectangle (balanced hips) shapes. |
| Pregnancy Changes | Waist expands dramatically during pregnancy as the uterus grows into the abdominal cavity. | Hips widen during pregnancy due to relaxin hormone loosening pelvic ligaments. |
| Weight Loss Pattern | Waist fat is typically lost first with caloric deficit, especially visceral fat. | Hip fat is often more resistant to loss, especially in females due to hormonal factors. |
| Genetic Heritability | Waist circumference heritability is moderate, around 30–40%, influenced by lifestyle. | Hip width is highly heritable, estimated at 60–70%, tied to pelvic bone structure. |
| Ethnic Variations | Asian populations tend to have higher visceral fat at lower waist circumferences. | African and Caribbean populations often have larger hip circumferences at similar BMIs. |
| Medical Imaging Reference | Waist CT or MRI scans measure visceral adipose tissue volume for metabolic research. | Hip DEXA scans measure subcutaneous fat and bone mineral density in the femoral neck. |
| Postural Support Role | Waist muscles stabilize the spine during lifting and twisting movements. | Hip muscles stabilize the pelvis during single-leg stance and gait cycles. |
| Injury Vulnerability | Waist is prone to lumbar strain and disc herniation from improper lifting. | Hips are prone to bursitis, osteoarthritis, and fractures, especially in older adults. |
| Cultural Aesthetics | Small waist is historically prized in Western fashion, corsetry, and beauty standards. | Full hips are celebrated in many African, Latin American, and Caribbean beauty ideals. |
| Cosmetic Surgery Target | Waist liposuction removes subcutaneous fat but does not reduce visceral fat. | Hip augmentation uses implants or fat grafting to increase outer hip projection. |
| Sports Performance | Narrow waist lowers rotational inertia, aiding golfers, boxers, and sprinters. | Wide hips increase hip abductor leverage, benefiting cyclists, runners, and weightlifters. |
| Best-Fit Scenario | Waist measurement suits metabolic health screening and tailored garment waistbands. | Hip measurement suits pelvic support assessment and lower-body athletic wear fitting. |
The waist is the narrowest part of the torso, located between the rib cage and the hip bones. It flexes and rotates the spine, supporting posture and movement. This anatomical region exists to distribute upper-body weight and enable bending, twisting, and core stabilization during daily activities.
The waist is the anatomical segment of the human trunk bounded superiorly by the lower rib margin and inferiorly by the iliac crest, typically marked by the natural indentation at the lateral sides. It contains the lumbar vertebrae, abdominal muscles, and vital digestive organs, serving as a flexible structural bridge between the thorax and pelvis.
| Characteristic | What It Means in Practice |
|---|---|
| Natural indentation | The inward curve visible from the front and side marks the transition between ribcage and pelvis, varying with body composition. |
| Bony landmarks | The lowest rib and top of the hip bone define the waist's upper and lower boundaries for consistent anatomical measurement. |
| Lumbar spine support | Five vertebrae in this region bear upper-body load and allow forward, backward, and rotational movements. |
| Muscular core | Transversus abdominis and obliques wrap the waist, compressing abdominal contents and stabilizing the trunk during exertion. |
| Fat distribution site | Subcutaneous and visceral fat accumulate here differently by sex, influencing metabolic health and waist circumference readings. |
| Flexibility range | The waist permits roughly 90 degrees of forward flexion and 30 degrees of extension, enabling bending and reaching tasks. |
| Proportional variability | Waist-to-hip ratio varies from 0.7 to 0.9 in healthy adults, reflecting genetic and hormonal influences on body shape. |
| Breathing involvement | Diaphragm attachments at the lower ribs mean deep inhalation expands the waist circumference noticeably. |
| Clothing reference point | Garment sizing uses the narrowest torso circumference, though high-rise versus low-rise styles shift where waistbands actually sit. |
| Postural alignment marker | A neutral waist position aligns the sternum over the pubic bone, preventing excessive lumbar lordosis or slouching. |
| Advantages | Limitations |
|---|---|
| Enables trunk rotation for reaching sideways and looking behind while driving or during sports. | Visceral fat stored here releases inflammatory cytokines that raise diabetes and heart disease risk. |
| Provides a reliable anthropometric proxy for total body fat when measured with standardized protocols. | Waist circumference alone cannot distinguish muscle mass from fat, misclassifying muscular athletes as overweight. |
| Facilitates breathing by allowing diaphragmatic descent and ribcage expansion during deep inhalation. | Age-related bone density loss and spinal compression reduce standing height, skewing waist-to-height ratio calculations. |
| Acts as a shock absorber, transmitting forces between the upper and lower body during walking and running. | Excessive lumbar lordosis from weak core muscles creates chronic lower back pain and poor posture. |
| Offers a visible indicator of weight change, as fat loss often appears here before other body regions. | Genetic predisposition determines waist shape, so some individuals cannot achieve a narrow waist despite exercise. |
| Supports garment design by providing a natural anchor point for belts, waistbands, and structured tailoring. | Waist measurement varies up to 5 centimeters with breathing, posture, and time of day, reducing repeatability. |
| Houses the rectus abdominis, which protects internal organs and generates force for lifting and throwing. | Diastasis recti after pregnancy weakens the waist wall, requiring surgical repair when exercise fails. |
| Contributes to balance by shifting the center of gravity during dynamic movements like twisting or leaning. | Waist training corsets compress organs and ribs, potentially causing breathing restriction and digestive issues. |
| Provides a simple screening tool for metabolic syndrome when combined with blood pressure and glucose readings. | Racial and ethnic differences in body proportions mean a single waist cutoff misclassifies risk across populations. |
| Allows precise anatomical referencing for medical imaging, surgical incisions, and acupuncture point location. | Neuropathic pain from lumbar nerve compression can radiate through the waist, mimicking organ disease and complicating diagnosis. |
Hips are the lateral bony prominences formed by the ilium, ischium, and pubis bones. They connect the lower limbs to the pelvis, enabling weight-bearing, locomotion, and balance. Their structure supports standing, walking, running, and sitting while protecting reproductive and digestive organs.
Hips are the anatomical region where the femur articulates with the pelvic girdle at the acetabulum, forming a ball-and-socket joint. This joint provides a wide range of motion in multiple planes, including flexion, extension, abduction, adduction, and rotation, while transmitting axial loads from the spine to the lower extremities.
| Characteristic | What It Means in Practice |
|---|---|
| Ball-and-socket joint | Allows circular movement and rotation, giving the leg a 360-degree range of motion for diverse activities. |
| Weight-bearing structure | Transfers upper body weight to the femurs during standing, walking, and lifting, distributing stress evenly. |
| Acetabular labrum | A fibrocartilage rim deepens the socket, improving joint stability while reducing friction during movement. |
| Strong ligamentous capsule | Iliofemoral, ischiofemoral, and pubofemoral ligaments reinforce the joint, preventing dislocation during extreme motion. |
| Large muscle attachments | Gluteal, hamstring, and iliopsoas muscles anchor here, generating powerful hip extension and flexion forces. |
| Sexual dimorphism | Female hips are typically wider and shallower to facilitate childbirth, while male hips are narrower and deeper. |
| Bony landmarks | Greater trochanter and iliac crest serve as palpable reference points for clinical exams, injections, and surgical incisions. |
| Nerve supply | Sciatic, femoral, and obturator nerves innervate the region, providing sensation and motor control to the leg. |
| Blood supply | Medial and lateral circumflex femoral arteries feed the femoral head, which is critical for preventing avascular necrosis. |
| Joint capsule fluid | Synovial fluid lubricates the articular surfaces, reducing wear and enabling smooth, pain-free motion over decades. |
| Advantages | Limitations |
|---|---|
| Enables bipedal locomotion with efficient energy transfer from torso to legs over long distances. | Prone to osteoarthritis due to heavy cumulative loading, causing pain, stiffness, and reduced mobility in older adults. |
| Provides exceptional stability during single-leg stance, crucial for walking, running, and balancing on uneven terrain. | Limited internal rotation range compared to the shoulder, restricting certain overhead or cross-body movements. |
| Supports powerful force generation for jumping, kicking, and lifting heavy objects using large gluteal muscles. | Susceptible to fractures in the femoral neck or intertrochanteric region, especially in osteoporotic elderly individuals. |
| Allows shock absorption during heel strike, dissipating ground reaction forces before they reach the spine. | Deep joint position makes surgical access difficult, requiring complex approaches that risk nerve or vessel damage. |
| Facilitates childbirth in females through a wider pelvic outlet, accommodating fetal passage during delivery. | Congenital dysplasia can cause hip dislocation in infants, leading to lifelong gait abnormalities if untreated. |
| Distributes body weight over a broad articular surface, reducing peak pressure on any single cartilage point. | Avascular necrosis of the femoral head can develop after trauma or steroid use, causing bone death and collapse. |
| Provides a stable base for trunk rotation, enabling activities like golf swings, dancing, and throwing motions. | Bursitis or tendinitis from overuse can cause lateral hip pain, limiting running, cycling, or prolonged sitting. |
| Offers a large muscle attachment area, allowing multiple muscles to work together for coordinated movement. | Nerve entrapment (e.g., sciatica) can radiate pain down the leg, mimicking lower back issues and complicating diagnosis. |
| Adapts to varied terrains through subtle adjustments in joint angle, maintaining balance on slopes or stairs. | Total hip replacement has a finite lifespan (15-25 years), requiring revision surgery in younger, active patients. |
| Enables cross-legged sitting and squatting postures, important for cultural practices, yoga, and certain occupations. | Ligament laxity can lead to instability or dislocation, particularly in athletes performing high-impact twisting movements. |
| Shared Aspect | How Waist and Hips Are Alike |
|---|---|
| Anatomical Location | Both the waist and hips are part of the human torso's lower region, connecting the upper body to the lower limbs. |
| Bony Landmarks | The waist and hips are both defined by underlying skeletal structures, including the ribcage and the pelvic bones respectively. |
| Muscle Attachment Sites | Both the waist and hips serve as attachment points for major core and lower body muscles, such as the obliques and gluteals. |
| Fat Storage Areas | The waist and hips are both common subcutaneous fat storage depots in the human body, though distribution varies by gender. |
| Body Measurement Points | Both the waist and hips are standard anthropometric measurement sites used for clothing sizing and health assessments. |
| Postural Support | Both the waist and hips contribute to maintaining upright posture by stabilizing the spine and pelvis during standing and sitting. |
| Movement Coordination | The waist and hips work together to enable bending, twisting, and rotating movements of the trunk and lower extremities. |
| Weight-Bearing Functions | Both the waist and hips transmit body weight from the upper body to the lower limbs during walking and running activities. |
| Flexibility Zones | The waist and hips are both regions of significant flexibility, allowing for a wide range of motion in daily activities. |
| Injury Susceptibility | Both the waist and hips are prone to strains and sprains due to their high mobility and load-bearing roles in physical exertion. |
| Age-Related Changes | The waist and hips both experience changes in fat distribution and muscle mass as a person ages, affecting their contours. |
| Exercise Targets | Both the waist and hips are common targets for fitness routines, with exercises like side planks and squats focusing on these areas. |
| Clothing Fit Determinants | Both the waist and hips are critical measurements for determining the fit of pants, skirts, and dresses in apparel manufacturing. |
| Body Mass Index Factors | The waist and hips are both used in calculating body composition metrics, including waist-to-hip ratio for health risk assessment. |
| Circulatory Pathways | Both the waist and hips contain major blood vessels that supply oxygenated blood to the lower body and return deoxygenated blood to the heart. |
| Nerve Innervation | The waist and hips are both innervated by spinal nerves from the lumbar and sacral plexuses, providing sensation and motor control. |
| Lymphatic Drainage | Both the waist and hips have lymph nodes that filter bodily fluids and support immune function in the lower torso. |
| Skin Elasticity | The waist and hips both have skin that stretches during weight changes, pregnancy, or growth, often leading to stretch marks. |
| Hormonal Influence | Both the waist and hips are influenced by sex hormones, which determine fat deposition patterns and bone structure during puberty. |
| Genetic Variability | The waist and hips both exhibit significant genetic variation in size and shape across different ethnic groups and individuals. |
| Thermoregulation Role | Both the waist and hips contribute to body temperature regulation through the distribution of insulating fat and blood flow. |
| Proprioceptive Feedback | The waist and hips both contain sensory receptors that provide feedback on joint position and movement to the brain. |
| Core Stability Contribution | Both the waist and hips are integral to core stability, helping to protect the spine during lifting and twisting motions. |
| Gait Cycle Participation | The waist and hips both move rhythmically during walking, with the waist rotating slightly and the hips swinging to maintain balance. |
| Pregnancy Adaptations | Both the waist and hips undergo structural changes during pregnancy, including ligament relaxation and weight redistribution. |
| Sports Performance Factors | Both the waist and hips are crucial for athletic performance, influencing speed, agility, and power generation in sports. |
| Ergonomic Considerations | Both the waist and hips are key reference points in ergonomic design for seating, workstations, and tool handles to reduce strain. |
| Rehabilitation Focus | Both the waist and hips are common focuses in physical therapy rehabilitation after lower back or pelvic injuries. |
| Cosmetic Enhancement Sites | Both the waist and hips are areas where cosmetic procedures, such as liposuction or fat grafting, are performed to alter body shape. |
| Long-Term Health Indicators | Both the waist and hips serve as long-term health indicators, with waist-to-hip ratio linked to cardiovascular and metabolic disease risks. |
The difference between waist and hips comes down to your measurement goal. For clothing fit and health risk screening, waist is the primary metric. For bottom garments and body shape analysis, hips matter more. The one variable that decides it for most people is what you are measuring for: health tracking requires waist, while apparel sizing requires hips.
Choose Waist when assessing metabolic health or fitting tops and dresses. The waist is the narrowest part of your torso, typically located above the belly button. Use a tape measure at this point for accurate readings. Health guidelines use waist circumference to screen for cardiovascular risk. For men, a waist over 40 inches signals higher risk; for women, the threshold is 35 inches. Waist measurements also determine sizing for high-waisted pants and fitted shirts.
Choose Hips when selecting pants, skirts, or evaluating body shape proportions. The hips are measured at the widest part of the buttocks, which is usually the fullest area below the waist. This measurement is critical for bottom garment sizing, as hip circumference determines fit across the seat and thigh. The waist-to-hip ratio also helps classify body shapes like pear or apple. For accurate hip measurement, stand with feet together and wrap the tape around the fullest part of your glutes.
| Common Myth | The Reality |
|---|---|
| "Your waist is the narrowest part of your torso." | The waist is the smallest circumference between the ribs and iliac crest, but the true anatomical waist sits above the navel, not at it. |
| "Hips and waist are the same measurement in most people." | The hip circumference is typically 8–10 inches larger than the waist in women, and 4–6 inches larger in men. |
| "Waist size is determined only by belly fat." | Waist circumference includes subcutaneous fat, visceral fat, muscle mass, and bone structure; belly fat is just one component. |
| "Hip width is purely genetic and cannot change." | Hip size changes with muscle mass, fat distribution, and age; gluteal training can increase hip circumference by 1–2 inches. |
| "Measuring hips at the widest point is always correct." | The standard hip measurement is at the greatest protrusion of the buttocks, but this point varies with posture and muscle development. |
| "A smaller waist always means better health." | Waist below 31.5 inches for women and 37 inches for men is healthy, but extreme smallness can indicate malnutrition or muscle loss. |
| "Waist-to-hip ratio is outdated and useless." | WHO still uses waist-to-hip ratio; a ratio above 0.85 for women and 0.90 for men indicates higher cardiovascular risk. |
| "Your hip bones determine your hip measurement." | Hip measurement includes the greater trochanter, gluteal muscles, and fat pads; bone width alone accounts for only 30–40% of hip size. |
| "Waist training permanently reduces waist size." | Corsets only compress soft tissue temporarily; waist size returns within weeks after stopping, and no permanent bone or muscle change occurs. |
| "Men don't need to measure their hips." | Men's hip measurement is essential for metabolic syndrome screening; a hip circumference below 40 inches with high waist increases diabetes risk. |
| "The waist is located at your belly button." | The anatomical waist is the narrowest point above the umbilicus, usually 0.5–1 inch above the navel in most adults. |
| "Hips and buttocks are the same thing." | Hips refer to the lateral pelvic region and greater trochanter area, while buttocks are the gluteal muscles and overlying fat posteriorly. |
| "Losing weight reduces waist and hip size equally." | Fat loss is not uniform; women lose hip fat slower than waist fat due to higher alpha-adrenergic receptor density in gluteal fat. |
| "A high waist-to-hip ratio only affects heart health." | Elevated waist-to-hip ratio also increases risk for type 2 diabetes, hypertension, stroke, and certain cancers, not just heart disease. |
| "Your waist measurement stays the same all day." | Waist circumference fluctuates 1–2 inches daily due to food intake, bloating, and posture; measure in the morning on an empty stomach. |
| "Hip implants are the only way to increase hip size." | Gluteal hypertrophy from resistance training adds 1–3 inches to hip circumference naturally, without surgery or implants. |
| "Waist size is more important than hip size for clothing fit." | Pants fit depends on both waist and hip; a 2-inch hip difference changes the garment silhouette even if waist matches perfectly. |
| "Body mass index (BMI) accounts for waist and hip differences." | BMI ignores fat distribution entirely; two people with the same BMI can have very different waist-to-hip ratios and health risks. |
| "Your waist-to-hip ratio is fixed after puberty." | Hormonal changes, pregnancy, menopause, and aging shift fat distribution, altering waist-to-hip ratio by 0.05–0.15 over a lifetime. |
| "Measuring hips requires removing all clothing." | Thin clothing adds only 0.2–0.4 inches; measure over underwear or thin leggings for consistent, accurate hip circumference readings. |
| "Waist and hip measurements are only for women." | Tailors, doctors, and fitness professionals measure waist and hips for men too; men's suits and health screenings depend on both values. |
| "Spot reduction can shrink your waist without losing overall fat." | Targeted exercises like crunches do not reduce waist fat; overall caloric deficit is required, and genetics dictate where fat leaves first. |
| "Hip circumference includes the widest part of the thighs." | The hip measurement stops at the gluteal fold; thigh circumference is a separate measurement taken 1–2 inches below the hip crease. |
| "A waist larger than hips always means obesity." | An "apple-shaped" body with waist > hips can occur in normal-weight individuals; it still signals higher visceral fat and metabolic risk. |
| "Your waist measurement is the same as your natural belt line." | Most people wear belts below the anatomical waist; the natural waist is higher, near the navel, where the torso bends sideways. |
| "Hip bone width increases with weight gain." | Bones do not widen with fat gain; the greater trochanter is fixed, but fat over the hips and upper thighs increases the tape measure. |
| "Waist-to-hip ratio is the same as waist-to-height ratio." | Waist-to-hip ratio divides waist by hip circumference; waist-to-height ratio divides waist by height, and a value above 0.5 indicates risk. |
| "Pregnancy permanently increases hip measurement." | Hips widen during pregnancy due to relaxin hormone, but most women lose 1–2 inches within 6 months postpartum; some permanent widening remains. |
| "You can accurately measure your own hips with a mirror." | Self-measurement of hips is often off by 1–2 inches due to tape angle; have a friend measure or use a wall for reference. |
| "Waist and hip measurements are interchangeable for health screening." | Waist alone predicts visceral fat, but waist-to-hip ratio captures gluteal fat's protective effect; using only one misses crucial information. |
Difference Between Waist and Hips comes down to anatomy and measurement. The waist is the narrowest part of your torso, above the navel. Hips are the widest point around the buttocks. Measure your waist for health risks; measure hips for fit. Choose waist for torso length, hips for lower-body sizing.
## FAQ ### What is the difference between waist and hips? The waist is the narrowest part of your torso, located above the navel, while the hips are the widest part around the pelvic bone and buttocks; waist-to-hip ratio is a key health metric. ### How do you measure your waist and hips correctly? Measure the waist at the narrowest point, typically just above the belly button, and the hips at the widest circumference around the buttocks; use a flexible tape measure for accuracy. ### Which is more important for health, waist or hip size? Waist size is more important for health because excess abdominal fat increases the risk of heart disease and diabetes; a waist-to-hip ratio above 0.90 for men and 0.85 for women signals higher risk. ### What is a healthy waist-to-hip ratio? A healthy waist-to-hip ratio is below 0.90 for men and below 0.85 for women, according to the World Health Organization; higher ratios indicate central obesity and elevated cardiovascular risk. ### Is it safe to reduce hip size through exercise? Yes, it is safe to reduce hip size through a combination of cardiovascular exercise and strength training, but spot reduction is a myth; overall fat loss will gradually shrink hip measurements. ### Do waist and hip measurements change with age? Yes, waist and hip measurements change with age because muscle mass decreases and fat redistributes to the midsection; hip width can also narrow due to bone density loss after menopause. ### What is the beginner mistake when measuring waist and hips? The beginner mistake is measuring over clothing or pulling the tape too tight, which adds inches or compresses tissue; always measure directly on bare skin and keep the tape snug but not indenting. ### Can you use waist and hip measurements interchangeably for clothing? No, you cannot use waist and hip measurements interchangeably for clothing because pants and skirts require both dimensions for fit; a garment sized for your waist may be too tight or too loose across the hips. ### What is the real-world use case for knowing your waist and hip sizes? The real-world use case is selecting properly fitting trousers, skirts, and athletic wear, and also tracking health changes; consistent measurements help tailor clothing and monitor weight-loss progress over months. ### Can I switch from using hip size to waist size for fitness tracking? Yes, you can switch from using hip size to waist size for fitness tracking, but waist circumference is a stronger predictor of metabolic health; combine both for a complete picture of body composition changes.