What causes leg cramps? Why they happen and what you can do.
A sudden, sharp pain grabs your leg and stops you in your tracks. Sound familiar? Whether it strikes in the middle of a workout or wakes you up in the middle of the night, a leg cramp can be intense, unexpected and frustrating. But what actually causes them?
Leg cramps are common, especially in adults. While they’re usually not serious, they can still interfere with sleep, exercise, or daily movement. Understanding what triggers these painful muscle spasms can help you manage them better. In some cases, it may help you avoid them altogether.
What causes leg cramps?
Leg cramps happen when a muscle tightens suddenly and doesn’t relax right away. Most of the time, they affect the calf muscles, but they can also show up in the thighs or feet. While the exact cause isn’t always clear, several common triggers may be to blame.
Overuse or muscle fatigue.
Exercising harder than usual, standing for long periods, or even walking more than normal can overwork your muscles. It’s one of the most common reasons people get cramps, especially after activity.
Dehydration and electrolyte imbalance.
If you're low on fluids (or key minerals like potassium or magnesium), your muscles are more likely to cramp. This is especially true during hot weather or after intense workouts. Always try to stay hydrated!
Poor circulation.
Reduced blood flow (whether from sitting too long or a circulation issue) can also lead to cramps. If your legs often feel tight or achy when walking or at night, this could be a factor.
Nerve compression.
Issues in the spine, like a herniated disc or spinal stenosis, can press on nearby nerves. In some cases, this can lead to cramping sensations in your legs.
Certain medications.
Some prescriptions (including diuretics, statins and medications for high blood pressure) can cause leg cramps as a side effect. If your symptoms started after a medication change, bring it up with your doctor.
Underlying health conditions.
In some cases, cramps can signal something deeper, like diabetes, thyroid issues, or kidney problems. If you’re experiencing frequent or severe cramps, it’s worth checking in with your primary care provider.
When leg cramps are more common.
Leg cramps can happen to anyone, but certain situations make them more likely. Understanding when and why they tend to occur can help you manage or avoid them altogether.
At night (nocturnal leg cramps).
It’s not unusual to be woken up by a sudden, painful cramp in your calf or foot. These nighttime cramps are especially common in older adults. They often strike without warning and may leave behind soreness even after the muscle lets go.
During or after exercise.
Cramps often show up after physical activity, especially if you push harder than usual, don’t warm up properly, or forget to stay hydrated. Long periods of standing or walking can also trigger them, particularly if your muscles are fatigued.
With age.
As we get older, our muscles lose elasticity and the nerves that control them may not function as efficiently. This can lead to more frequent cramping, even during low levels of activity or rest.
In hot weather.
Warm temperatures increase the risk of dehydration and electrolyte loss through sweating, which can make muscles more likely to cramp, especially during outdoor activities.
Knowing these patterns can help you take steps to lower your risk, whether that means stretching before bed or drinking more water on a hot day.
How to relieve and prevent leg cramps.
Most leg cramps go away on their own, but when they strike, the discomfort can be intense. But there’s good news. You can ease the pain when it happens and take simple steps to prevent future cramps, too.
What to do during a cramp.
- Gently stretch the muscle. If your calf cramps, try straightening your leg and flexing your foot toward your body. This can help release the spasm.
- Massage the area. Rubbing the muscle may increase blood flow and speed up recovery.
- Apply heat. A warm towel or heating pad can help relax tight muscles. For soreness afterward, cold packs may also help reduce inflammation.
- Walk it off. Light movement or pacing can sometimes help ease the tightness more quickly.
How to help prevent leg cramps.
- Stay hydrated. Dehydration is a major contributor to cramps. Drink water regularly throughout the day, especially in warmer weather or after physical activity.
- Stretch regularly. Gentle stretching before and after exercise—and even before bed—can keep your muscles flexible and less prone to spasms.
- Maintain a balanced diet. Make sure you’re getting enough magnesium, potassium and calcium. These electrolytes are key to healthy muscle function.
- Review your medications. If you’ve started a new prescription and notice more cramps, talk to your doctor. A simple adjustment may help.
- Exercise consistently. Staying active strengthens your muscles and improves circulation, which may reduce cramp frequency over time.
When to visit urgent care for leg cramps.
Most leg cramps aren’t serious, but if they’re happening often or are starting to affect your daily routine, it’s worth getting checked out. Cramping that’s frequent, painful, or accompanied by other symptoms could point to something more than just overuse or dehydration.
Visit a CityMD urgent care center if you experience:
- Severe or frequent cramps that don’t go away
- Swelling, redness, or warmth in the leg
- Tingling, numbness, or muscle weakness
- Pain that lasts even after stretching or resting
- A sudden increase in cramps after starting a new medication
At CityMD, our providers can evaluate your symptoms, rule out more serious causes and help you find relief. Need testing, a quick evaluation, or just peace of mind? Walk in today. No appointment needed.
We’re ready to care for you.
Visit any CityMD urgent care location in your community today for an evaluation with one of our expert providers.