Leg pain is a symptom of dozens of diseases, ranging from manageable chronic conditions to medical emergencies. The cause can originate in your blood vessels, nerves, joints, bones, or skin, and the type of pain you feel, where exactly it hits, and what makes it better or worse are the biggest clues to what’s behind it. Here’s a breakdown of the most common and most serious possibilities.
Peripheral Artery Disease
Peripheral artery disease (PAD) is one of the most important causes of leg pain to rule out, especially if you’re over 40. It happens when fatty deposits narrow the arteries that supply blood to your legs. During rest, the reduced blood flow is often enough to keep your muscles comfortable. But when you walk, climb stairs, or go uphill, your muscles need more oxygen than those narrowed arteries can deliver, and the result is cramping, aching, or burning pain, most often in the calf, thigh, or buttocks. This predictable pattern of pain during activity that goes away with a few minutes of rest is called claudication.
What makes PAD tricky is that many people write it off as normal aging. The American Heart Association has specifically cautioned against accepting “you’re just getting older” as an explanation for leg symptoms that change how far you can walk. The location of the pain maps directly to where blood flow is blocked. A simple, painless test that compares blood pressure in your ankle to blood pressure in your arm can flag the problem. A ratio of 0.90 or lower generally indicates PAD.
Blood Clots in the Leg
Deep vein thrombosis (DVT) occurs when a blood clot forms in one of the deep veins of your leg, usually in the calf. The hallmark is pain, swelling, and warmth in one leg but not the other. The skin over the clot may turn red or purple, and the area is often tender to the touch. Some people describe it as a deep cramp or soreness that starts in the calf and doesn’t go away with stretching.
DVT can also occur without any noticeable symptoms, which is part of what makes it dangerous. The real risk is that the clot breaks loose and travels to the lungs, causing a pulmonary embolism. If you develop sudden leg swelling along with chest pain or difficulty breathing, that combination needs emergency attention. Prolonged sitting, like a long flight or car ride, is a well-known trigger.
Chronic Venous Insufficiency
If your leg pain feels more like heaviness, aching, or cramping and gets worse the longer you stand, venous insufficiency is a likely culprit. This happens when the valves in your leg veins stop working properly, allowing blood to pool instead of flowing back up toward your heart. The pain typically improves when you elevate your legs. Over time, you may notice visible varicose veins, skin discoloration around the ankles, or swelling that worsens throughout the day.
Diabetic Neuropathy
Diabetes damages nerves over time, and the legs and feet are almost always affected first. The pattern is distinctive: symptoms start in the toes and feet, then gradually creep upward toward the knees, following a “stocking” distribution. The sensations include burning, tingling, sharp pains, and sometimes hypersensitivity so extreme that even the weight of a bedsheet becomes painful.
This type of nerve damage doesn’t just cause pain. It can also cause numbness, which creates its own danger. People with advanced diabetic neuropathy may not feel injuries to their feet, leading to infections and ulcers that go unnoticed. If you have diabetes and are experiencing any unusual sensations in your legs or feet, that’s worth addressing early, before the nerve damage progresses further.
Sciatica and Spinal Stenosis
Not all leg pain starts in the leg. The sciatic nerve runs from your lower back down the back of each leg, and when something presses on it, pain radiates along that entire path. A herniated disc in the lower spine is the most common cause. The pain typically shoots from the lower back through the hip and down one leg, sometimes all the way to the foot. Tingling, numbness, and muscle weakness on the affected side are common.
Spinal stenosis, a gradual narrowing of the space around the spinal cord, can produce similar symptoms but tends to develop more slowly. When the narrowing compresses the sciatic nerve, you get the same one-sided leg pain and numbness. The key difference from vascular causes like PAD is that nerve-related leg pain often worsens with certain positions (like sitting for long periods or bending backward) rather than purely with walking distance.
Arthritis Affecting the Legs
Rheumatoid arthritis can target several joints in the legs, including the toes, ankles, knees, and hips. A defining feature is morning stiffness lasting more than 60 minutes. The joints feel painful and stiff after sleeping or sitting still, then gradually loosen up with movement. Unlike osteoarthritis, which tends to affect one joint that’s seen heavy use, rheumatoid arthritis often involves the small joints of the feet and toes early on, and it typically affects both sides symmetrically.
Osteoarthritis, the wear-and-tear type, most commonly causes pain in the knees and hips. The pain tends to worsen with activity and improve with rest, which is roughly the opposite of the rheumatoid pattern. Both forms of arthritis produce pain that’s clearly centered on the joint itself rather than in the muscles or deep tissues between joints.
Cellulitis and Other Infections
Cellulitis is a bacterial skin infection that frequently targets the lower legs. The affected area becomes red, swollen, warm, painful, and tender to the touch. The skin may look pitted, almost like an orange peel, and blisters can form. Some people develop fever and chills alongside the spreading redness. If a red, warm area on your leg is expanding quickly or you spike a fever, that warrants urgent medical care because the infection can spread to deeper tissues rapidly.
How to Tell Muscular Pain From Something Deeper
The most common cause of leg pain is simple muscle strain or overuse, which usually has an obvious trigger: a new workout, a long hike, an awkward movement. It tends to improve steadily over days with rest and doesn’t come with swelling, skin changes, or systemic symptoms like fever.
Vascular and systemic causes of leg pain behave differently. PAD pain is reproducible, appearing at roughly the same point during a walk and disappearing with rest. DVT pain is persistent and usually one-sided, with visible swelling. Nerve pain follows specific pathways down the leg and often includes tingling or numbness. Joint pain is localized and tied to movement of that specific joint. These patterns are the most useful tools for narrowing down what’s going on before any tests are ordered.
Signs That Need Immediate Attention
Certain combinations of symptoms with leg pain are red flags. Get emergency help if you can’t walk or bear weight on the leg, or if you notice pain, swelling, redness, and warmth together in the lower leg (possible DVT). A leg that suddenly becomes pale, cold, or loses its pulse could signal a complete arterial blockage.
See a provider promptly if one leg is swollen and cooler than the other, if you develop calf pain after prolonged sitting, if you have signs of infection like spreading redness and fever above 100°F, or if both legs swell and you’re also having trouble breathing. Any serious leg symptom that appears without an obvious cause, like an injury or intense exercise, deserves medical evaluation rather than a wait-and-see approach.