Left leg pain can have many possible causes, ranging from minor injuries to serious medical conditions. Some of the most common reasons for left leg pain include:
Muscle strain
Muscle strains are one of the most common causes of left leg pain. They occur when the muscles are overstretched or torn. This often happens due to exercise, sudden movements, or sports injuries. Typical symptoms include pain, stiffness, and tenderness in the affected muscle.
Shin splints
Shin splints cause pain along the shin bone or tibia. They are often brought on by physical activity like running. The pain usually starts gradually and worsens with continued activity. Resting typically helps reduce the discomfort.
Knee injuries
Injuries to the knee joint, ligaments, cartilage, or bones can all trigger left leg pain. Some examples include:
- Sprains – Stretching or tearing of ligaments
- Tendonitis – Inflammation of a tendon
- Bursitis – Swelling of a bursa sac
- Fracture – Broken bone
Knee injuries often cause swelling, difficulty bending the knee, and a popping or locked sensation in the joint.
Arthritis
Arthritis leads to inflammation and damage within the knee joint. This wears down the protective cartilage and bones, leading to pain. The two main types that affect the knees are:
- Osteoarthritis – Most common type, caused by aging and wear and tear
- Rheumatoid arthritis – Autoimmune condition that can affect the knees and other joints
Tendon rupture
A tendon rupture means the tendon is partially or completely torn. This can occur with major injuries or as a result of long-term tendon damage. Ruptures often cause a popping sensation, immediate pain, and visible bruising.
Septic arthritis
Septic arthritis is inflammation in the joint due to a serious infection. It often starts suddenly with severe knee pain and swelling. Fever and chills may also be present. Septic arthritis requires prompt medical treatment before it destroys the joint.
Baker’s cyst
A Baker’s cyst is a fluid-filled swelling behind the knee. It’s caused by a buildup of synovial fluid in the joint that leaks into the back of the leg. Symptoms include swelling, tightness, and leg pain that may increase with activity.
Blood clot
A blood clot in a leg vein, known as deep vein thrombosis, can trigger left leg pain. Symptoms often start gradually and worsen over time. Swelling, tenderness, increased warmth, and skin discoloration may also occur.
Peripheral artery disease (PAD)
PAD causes the arteries supplying blood to the legs to narrow. This reduces blood flow, potentially leading to leg pain when walking and exercising. PAD leg pain often goes away with rest.
Diabetic neuropathy
High blood sugar levels from diabetes can damage nerves in the legs. This nerve damage or diabetic neuropathy can manifest as numbness, tingling, burning, or pain in the legs and feet.
Sciatica
The sciatic nerve runs down the back of each leg. If it’s compressed or irritated, it can trigger sciatica leg pain. Typical symptoms are shooting pain, numbness, and tingling down the back of the leg.
Muscular dystrophy
Muscular dystrophy is a group of inherited disorders that cause progressive muscle weakness over time. Leg pain and loss of mobility are common early signs as the leg muscles weaken.
Compartment syndrome
Compartment syndrome develops when swelling and pressure build up within a muscle compartment. This compression can cut off blood flow and cause severe leg pain. It often requires emergency surgery.
Stress fracture
A stress fracture is a small crack in a bone, most often caused by repetitive stress or overuse. Common sites include the tibia and fibula in the leg. Symptoms include swelling, bruising, and leg pain that worsens when bearing weight.
Bone tumor
Although rare, bone cancer can manifest with left leg pain if a tumor presses on tissues or damages part of the leg bone. Other possible symptoms include limping, swelling, and fatigue.
Accident injury
Major trauma from an accident like a car crash can fracture bones, tear muscles and ligaments, and damage nerves and blood vessels in the leg. This causes significant leg pain and disability.
Referred pain
Sometimes pain that originates elsewhere in the body can be felt in the left leg. For example, pain signals from kidney stones or a ruptured abdominal aneurysm can radiate down the leg.
Nerve root compression
Pressure on the nerve roots exiting the lower spine can radiate pain into the left leg. Common causes include a herniated disc or spinal stenosis from arthritis.
Complex regional pain syndrome
This chronic pain condition can initially develop after a leg injury. It causes severe, spreading pain, tenderness, swelling, numbness, and disability in the affected limb.
Piriformis syndrome
The piriformis muscle located deep in the buttocks can sometimes compress the sciatic nerve, triggering pain down the back of the leg.
Avascular necrosis
Avascular necrosis or osteonecrosis develops when part of a leg bone loses its blood supply and dies. This leads to collapse of the bone and deformity, causing persistent knee and leg pain.
Leg length discrepancy
If one leg is slightly longer than the other, it can tilt the pelvis and alter posture and gait. This may result in chronic leg, hip, or back pain on the side with the shorter leg.
Venous insufficiency
When leg veins can’t pump blood back to the heart properly, it leads to pooling in the lower legs. This often causes aching, throbbing leg pain that worsens with activity or as the day goes on.
Varicose veins
Enlarged varicose veins in the legs can ache, burn, itch, and even cause leg cramping for some people. The pain tends to worsen when standing or walking.
Vitamin deficiency
Deficiencies in certain vitamins including B vitamins and vitamin D can sometimes manifest with burning, tingling, or numbness in the legs and feet.
Lyme disease
Lyme disease contracted from tick bites may initially cause leg pain, joint swelling, and flu-like symptoms. Left untreated, it can progress to cause temporary leg paralysis.
Shingles
After exposure to the chickenpox virus, the shingles virus can reactivate years later, causing a painful rash and nerve inflammation. When shingles occurs on the leg, it leads to severe localized leg pain.
Endometriosis
Endometrial tissue growing outside the uterus can cause painful nodules to form around the pelvis and down the legs. Leg pain tends to worsen around the menstrual period.
Pelvic inflammatory disease
Infection and inflammation in the female reproductive organs often spreads to the uterus and fallopian tubes. This can refer pain down the thighs and legs.
Spontaneous coronary artery dissection
This rare emergency condition involves a tear inside a major heart artery wall. If it blocks blood flow, it may cause sudden onset leg pain along with chest pain.
Spinal stenosis
Narrowing of the spinal column puts pressure on the spinal nerves and often leads to lower back and leg pain. Symptoms worsen with standing and improve when sitting.
Herniated disc
If an intervertebral disc in the spine ruptures, it can press on a nerve root and radiate pain down the sciatic nerve into the leg and foot.
Hip bursitis
Inflammation in the bursa sacs around the hip joint can cause outer thigh and buttock pain. Pain may radiate down to the knee.
Trochanteric bursitis
Irritation of the bursa over the outer hip bone can trigger pain in the hip and down the outer thigh. Lying on the affected side worsens the discomfort.
Perthes disease
This hip disorder occurs when the blood supply to the femoral head is temporarily disrupted, leading to bone death. It causes limping, thigh pain, and limited range of motion.
Hip fracture
A broken hip bone, often occurring in elderly adults after a fall, produces sudden, severe groin and thigh pain. The leg may look shortened or rotated.
Paget’s disease of bone
This chronic disorder causes excessive bone breakdown and regrowth, leading to deformity. It can produce deep, aching thigh pain if the pelvis or femur are affected.
Bone metastases
The spread of cancer to the bones can weaken and destroy bone structure. Tumors in the pelvis or leg bones lead to localized leg pain and other symptoms.
Osteomyelitis
An infection in the bone causes severe tenderness, swelling, and fever. It often starts after an injury that exposes bone to bacteria.
Chiari malformation
This condition causes part of the brain to protrude into the spinal column, which can compress nerves. Shooting leg pains are common symptoms.
When to See a Doctor
Make an appointment with your doctor if you have any unexplained leg pain that:
- Is severe or persistent
- Worsens at night or with rest
- Spreads down the leg
- Causes numbness or tingling
- Occurs with swelling, redness, or warmth
- Happens after a major injury
- Impacts mobility or daily activities
Prompt evaluation is crucial to determine the underlying cause and get appropriate treatment. Call 911 immediately for leg pain that starts suddenly or feels life-threatening.
Diagnosing Leg Pain
To diagnose the cause of left leg pain, the doctor will typically:
- Ask about your symptoms and medical history
- Conduct a physical exam of the leg and joints
- Order diagnostic tests as needed, such as:
- X-rays
- MRI
- CT scan
- Ultrasound
- Electromyography
- Blood tests
Based on the test results and exam findings, the doctor will determine the underlying problem and best course of treatment.
Treatments for Left Leg Pain
Treatment varies depending on the diagnosed cause of the leg pain. Some general treatment approaches may include:
- Rest – Avoiding activities that worsen pain.
- Ice/heat – Applying ice packs or heating pads to relieve pain and inflammation.
- Compression – Using elastic bandages or compression stockings to prevent swelling.
- Elevation – Keeping the leg raised above heart level to aid circulation.
- Pain relievers – Over-the-counter medicines like ibuprofen or naproxen to reduce pain and inflammation.
- Physical therapy – Stretching and strengthening exercises to improve mobility and function.
- Bracing – Using splints or braces to stabilize joints or support muscles.
- Injections – Steroid injections into damaged joints or muscles to reduce inflammation.
- Surgery – For severe joint damage, fractures, or nerve compressions that don’t improve with other treatments.
Specific medical conditions may also require additional treatments, medications, or lifestyle changes. Work closely with your doctor to ensure proper management of your leg pain.
Prevention
While not all cases of left leg pain can be prevented, some general tips to help reduce your risk include:
- Maintain a healthy weight to minimize pressure on joints and bones.
- Warm up properly and stretch before exercise or physical activity.
- Use proper form and technique during sports and fitness training.
- Wear supportive footwear with adequate cushioning.
- Avoid high-impact activities if you have existing joint or bone problems.
- Listen to your body and rest when you start having leg discomfort.
- See your doctor if you have severe or recurring leg pain.
- Manage medical conditions like diabetes to prevent nerve damage and poor circulation.
- Quit smoking since it constricts blood vessels and may worsen leg pain.
Conclusion
Left leg pain can stem from injuries, overuse, chronic conditions, or even an underlying medical emergency. While the causes are wide-ranging, prompt evaluation and treatment can identify the problem and help reduce discomfort and disability. Persistent, worsening, or unexplained leg pain should never be ignored.