How much you sweat during any workout or physical activity depends on a lot of factors, says Lindsay Bordone, MD, a dermatologist at Columbia University Medical Center in New York City. How humid is it? How hot is it? How hard are you pushing yourself? How quickly are you moving? How hydrated are you? What did you eat beforehand? Inconvenient as it sometimes may be (sweaty palms as you head into a job interview?), sweating is normal — and an absolutely crucial bodily function. RELATED: 6 Fascinating Facts You Probably Never Knew About Your Skin “One of the main functions of sweating is to aid the body in maintaining homeostasis, or balance, in the body,” explains Grayson Wickham, CSCS, a New York City–based physical therapist and the founder of Movement Vault, a mobility and movement company. If your body temperature gets too high, it can be harmful to your cells. Sweating helps the body avoid reaching that point, he says: “It’s one of our main mechanisms for cooling." What exactly happens when you sweat? When your core body temperature gets too high, you produce moisture on the surface of the skin. Evaporation of that moisture cools the skin. RELATED: Everything You Need to Know About Fitness (and Why It’s So Important for Health)

There Are a Lot of Very Healthy Reasons You May or May Not Sweat as Much as Someone Else

Again, how much you sweat depends on a lot of factors — and it’s worth noting that there’s a pretty wide range of what’s considered normal and healthy when it comes to sweating. From the get-go, genetics determine how much (or little) you sweat to some degree, Wickham explains. Some people are born with genes that make them tall; some people are born with genes that make them sweat more than others (with several of those extra variables being consistent). Beyond that, things like feeling anxious, an underlying health condition (like type 2 diabetes and certain thyroid conditions), and some medications, among others, can all increase sweat production. Hydration status has an impact on how much you sweat, too. “Someone who is well hydrated will sweat more than someone who is less hydrated,” Wickham says. Same goes for people with higher fitness levels, he adds. The more conditioned your body is to exercise, the sooner it may ramp up sweat production to keep you cool while you train. The bottom line: In most cases, it’s totally normal to be drippier (or drier) than your hot-yoga buddy on any given day. But in some cases, sweating too much or too little may indicate that you have an undiagnosed medical problem. Hyperhidrosis is a chronic medical condition characterized by excessive sweating that is frequent, difficult to control, and not necessarily triggered by heat or exercise. Hypohidrosis, also called anhidrosis, is a chronic medical condition characterized by not sweating enough. RELATED: 9 Ways to Help Get Excessive Sweating (Hyperhidrosis) Under Control

All About Hypohidrosis (Anhidrosis)

According to the Mayo Clinic, hypohidrosis occurs when your sweat glands don’t function properly and, as a result, block your ability to sweat. Though dehydration can cause short-term hypohidrosis, some people deal with a chronic lack of sweating that they were either born with or developed later in life. Cases of hypohidrosis that are purely genetic (people born with the condition) are incredibly rare. More often, people have hypohidrosis because of conditions or injuries that affect the nerves or skin, such as diabetes or psoriasis, according to the U.S. National Library of Medicine. Certain medications — namely antipsychotics — can also affect sweat gland function and contribute to hypohidrosis, according to the Cleveland Clinic. The scientific community has limited data on the true prevalence of hypohidrosis because doctors suspect that many mild cases go undiagnosed, according to the International Hyperhidrosis Society. The 2016 practice guidelines published in The Journal of Dermatology state that cases are very rare, and it is suspected that many cases go unreported. Severe cases of hypohidrosis are typically diagnosed quickly in infancy or childhood, but less severe cases often aren’t diagnosed until later in life — if at all.

Why Sweating Too Little Can Be a Problem

Not sweating enough can bring on some potentially serious health risks. If hypohidrosis affects a large portion of your body and prevents proper cooling, then vigorous exercise, hard physical work, or hot weather can cause heat cramps, heat exhaustion, or even heatstroke. The condition can lead to more serious complications in children because their bodies’ core temperatures rise more quickly than adults’ body temperatures do — and children release body heat less effectively, according to the Mayo Clinic. RELATED: How to Avoid Heatstroke — and Other Summer Health Hazards “The condition is dangerous because these people can overheat internally, which can lead to death in severe cases,” says Dr. Bordone, adding that even in milder circumstances, “patients with hypohidrosis would likely have an inability to tolerate exercise or high temperatures.” In addition to their lack of sweat, people with hypohidrosis may notice that they feel dizzy, weak, or excessively hot incredibly easily. They may also experience flushing of the skin and muscle cramps.

How to Tell if Your Lack of Sweat Is a Problem

If you don’t seem to sweat as much as others around you, it doesn’t necessarily mean that you have hypohidrosis. “Some people do not sweat a lot at baseline while some people do,” says Bordone. “Different people have different numbers of sweat glands and a different genetic makeup.” As long as your sweat (or lack thereof) does not interfere with your daily routine (exercise included!), it’s likely not a medical concern. However, if you experience any of the symptoms of hypohidrosis (such as flushing of the skin and being easily fatigued), avoid heat or strenuous exercise because of concerns about your lack of sweat, or have had multiple heat strokes, check in with your doctor, Bordone recommends. Also see your doctor if there’s a notable decrease in how much you usually sweat. Hypohidrosis can indicate health conditions such as hypothyroid disease, so it’s important to get checked out, Bordone adds. In some serious cases of hypohidrosis (particularly among children), doctors may recommend cooling vests so people can participate in various activities more safely, says Bordone. In other cases, they may prescribe medication that causes sweating, according to the National Institutes of Health. Although specific treatments for hypohidrosis depend on the reason for your lack of sweat, your healthcare provider will generally work with you to manage your lifestyle and prepare for situations in which heat might put your health at risk. An unfortunate but often necessary reality: Many people who can’t properly cool off because of a lack of sweat should avoid high-intensity exercise and heat.