Leg pain can be dull or severe depending upon the cause of the pain. There are multiple causes of leg pain which can be accidental, non-accidental, or medical conditions. These conditions can cause upper leg or thigh pain as well as lower leg or shins pain. The nature of leg pain depends on the cause of pain whether it is discomfort, dull ache, throbbing, or stabbing pain. Some of them are self-limiting and require no medical attention while others may require medical intervention to get resolved.

Causes of Leg Pain

There are 2 main categories in which we will discuss different causes of leg pain.

a) Accidental Causes

b) Medical Conditions

a) Accidental causes of Leg Pain

In the case of children and young adults, the most common cause of leg pain is due to sports or accidental falls. Chances of injury are higher in social sports like football, soccer, cycling, skateboarding, and wrestling. In these types of injuries, knees, ankles, and feet are the most vulnerable parts of the body. 

1. Sprains

A stretch or a tear of a ligament is called a sprain. A ligament is the fibrous band of tissue that helps to connect two bones of the joint to support them. The ankle is the most common part of a sprain. A sprain can be caused during landing from a high place with a jump or twisting of the ankle while running.

2. Strain

Excessive stretch or a tear of the muscle is called a strain is commonly known as a pulled muscle. This is quite a common condition in people who plays recreational sports. The nature of pain is severe and intense.

3. Stress Fractures

A stress fracture is unlike other bone fractures which occur due to a single severe impact. A stress fracture occurs when there are repeated episodes of stress over time. It can also be described as a “hairline fracture”. Stress fractures of the foot are also known as “March fractures” because of their high prevalence in soldiers who march heavily.

4. Achilles Tendinitis

Achilles tendon is a tendon which connects calf muscles to the heel. When the Achilles tendon is continuously being overused, it becomes sore. This overuse changes the structure as well as mechanical properties of the tendon, resulting in pain, stiffness, and swelling of the affected tendon. This is called Achilles tendinitis or Achilles tendinopathy. It is more common in runners. The typical pattern of pain is getting worse at the start of exercise and decreases when exercise stops.

Medical Conditions Causing Leg Pain

1. Cellulitis

Cellulitis is the inflammation of the dermis and subcutaneous tissue. The lower leg is often involved and mainly develops on shins. Cellulitis begins with a tender small patch. Inflammation, pain, and redness are often present. Gram-positive cocci are the most commonly responsible organism for this condition. Lymphangitis and lymphadenopathy are often present. Septicemia may also develop. Intravenous or parenteral antibiotics may be required as an initial step of management.

2. Peripheral Artery Disease

Peripheral artery disease causes blockage or narrowing of the blood vessels which carry blood from the heart to the lungs. It mainly affects the lower extremities of the body but can affect the upper extremities as well. Intermittent Claudication is the most remarkable feature of PAD which is cramping pain or tiredness induced by walking and relieved by rest. Critical limb ischemia is another hallmark feature of PAD which includes 6P’s that are pallor, pain, paresthesia, paralysis, pulselessness, and poikilothermia. It can be managed accordingly.

3. Deep vein thrombosis(DVT)

Blood clot formation in the deep veins of the body particularly the legs is called deep vein thrombosis. It commonly affects the lower extremities or pelvis but can also be found in the upper extremities. Certain risk factors are responsible for this condition which includes pregnancy, obesity, smoking, and heart problems. There is throbbing or cramping leg pain. It usually affects one leg but can involve both.

4. Sciatica

When the sciatic nerve gets compressed or injured, this leads to sciatica. In this condition, pain follows the path of the sciatic nerve. Pain radiates from the buttock down to the leg and can travel to the feet and the toes. The nature of pain is often throbbing or shooting. Tingling or burning sensation is also reported by patients.

5. Restless Leg Syndrome

 An irresistible urge to move the leg associated with uncomfortable or unpleasant feelings in the leg is called restless leg syndrome. It is also known as Willis-Ekbom disease. Commonly, the symptoms arise in the evening and become severe in the night when the patient is sitting or lying. This syndrome causes severe sleep disturbance that can lead to daytime sleepiness.

6. Varicose Veins

Varicose veins develop due to long periods of high venous pressure related to prolonged standing or heavy lifting. High-risk patients are women after their pregnancy. Presenting features include dilated, torturous superficial veins in the legs. There may be aching discomfort or pain in the legs. 

7. Compartment Syndrome

Compartment syndrome is a painful condition that occurs when the pressure within the muscle builds up to a dangerous level. This pressure can decrease the blood flow that prevents nourishment and oxygen from reaching muscles and cells. Symptoms may include pain while stretching the involved muscle. Numbness or paralysis is late signs of compartment syndrome.

8. Electrolyte Imbalance

It can be due to hypercalcemia or hypocalcemia. In Hypercalcemia, the calcium level of the body rises above normal. It can be due to the overactivation of the parathyroid hormone.  Symptoms include fatigue and bone pain, particularly in the legs.

In hypocalcemia, the calcium level of the body decreases below normal. It can be due to osteoporosis or osteopenia. Symptoms include muscle cramps and spasms, tingling and twitching of muscles.

9. Spinal Stenosis

When the pressure on the spinal cord or nerve root increases due to the narrowing of spaces within the spine, the resulting condition is called spinal stenosis. The common presentation of spinal stenosis is numbness, tingling sensation associated with weakness, and pain in the arm or leg.