Left Leg Numb: Heart Attack?


If you have been sleeping on an arm or sitting on one leg for a long time, you will not feel slight touch, pain and temperature which is considered as numbness.

The cause of limb numbness is due to compression of the nerve in that area. For example, “when you are sitting on one leg for long time” or due to any serious conditions.It can be in one side or both side of our body.

The aim of this article is to specifically highlight the left leg numb and knowledge on it’s cause, complication, prevention, diagnosis and when you must to go to a doctor.

What can cause left leg pain or numbness?

The leg is composed of bone, nerve, muscles, connective tissue and blood vessels. If any of these components damage can lead to leg pain .causes of left leg pain are:1

1. When you doing extensive exercise.

2. Injury to the nerve that supply the left leg.

3. Muscle, ligament or tendon strains.

4. Chronic pain and tenderness of muscle, tendon and joint .

5. Nerve damage.

6. Disease of spinal cord (where the nerve originates).

7. Diabetic person may have leg pain because increasing level of sugar can damage the nerve.

8. Osteoporosis: a disease specially In women after the end of menstruation (menopause) the bones become porous and subject to fracture.

9. Blood clot and peripheral artery disease( PAD).

10. Inflammation of the joint (arthritis)

11. Poor circulation or cardiac disease.

What is peripheral artery disease?

Peripheral artery disease(PAD) is circulatory problem causing decreasing in blood flow through arteries. It is seen to increase with people over the age of 70 and smoker person. It is due to the closure of artery or blood vessels caused by accumulation of fats, usually cholesterol “plaque” (blood clot) and scientifically called atherosclerosis in the abdominal aorta, iliac and femoral artery.

In early stage of PAD the artery dilated to compensate with plaque to allow flow through the vessels (asymptomatic stage). ln late stage the artery cannot dilate any more so the atherosclerotic plaque begin to narrow the blood vessels lumen that result in decreasing blood flow.

When blood flow to nerve is decreased pain in the sole, feet and leg can be experienced. In severe situation the toes or the fore foot can turn into black which is called gangrene.2

Signs and symptoms

Muscle leg pain during walking is the most common symptom of PAD. It is due to blood clot blocking the blood flow leading to insufficient oxygen supply to muscle. Other symptoms include:3

• Poor healing of foot or toe injury 

• Dead tissue

• Decrease in leg temperature compare to other part of the body.

• Erectile dysfunction in diabetic person.

Causes and risk factors

The cause of PAD is because of narrowing the blood vessel which due to blood clot, as a result the blood flow decreases.

The most important risk factor of PAD is:4

1. Increasing age

2. Smoking and tobacco usage

3. Type 2 diabetes 

4. High blood pressure (silent killer)

5. High blood cholesterol which causes blood clot 

• If you don’t have symptoms but you have one of these risk factors, you must consult a doctor.


The most important complication of PAD is heart attack .

Heart Attack

Our heart act as pump to supply blood to our entire body with oxygen and nutrient that are needed for growth. This pump also need oxygen to perform its job. The artery that carry oxygen to the heart is called ‘coronary artery’. When they are accumulated with fat (blood clot), oxygen can not reach heat muscle which is called ischemia. This results in death of part of heart muscles and it’s called heart attack 5.


Start with medical history to check any risk factors of PAD and physical examination which include:6

• Ankle-brachial Index (ABI): The basic idea of this exam to compare the blood pressure in lower leg to blood pressure in arm 

• Visualize the artery sound waves and measures the blood flow to detect blood clot (Duplex ultrasonography)

• Computer tomography (CT) 

• Angiography: create picture of blood vessels of the abdomen, leg and pelvic by using x ray and dye.

• Cross sectional image without using x-ray ( Magnetic resonance angiography (MRI).

• If they are more than one artery block we can use peripheral angiogram to detect the narrowed artery in the leg, feet or in hand and arm by using x-ray and contrast dye.

Treatment and prevention

Basics on reducing symptoms and prevent progression of disease include: 7

1. Behavior modification, nicotine replacement medicine and other smoking medications to treat smokers.

2. Physical exercises like simple walking with intervals and leg exercise.

3. Eating vegetables, fruits, whole grains and low fat diet to solve the high cholesterol levels.

4. Use of anti platelet agents to prevent blood clot formation (e.g: Asprin)

5. Medication to lower cholesterol levels (e.g:statins) 

6. High blood pressure medication.

NOTE: One must consult a doctor for proper medication and treatment according to their situation. 

When to see a doctor

One should consult a doctor without any delay, when you feel above mentioned signs and symptoms of PAD like leg pain and numbness of the leg or if you have one of the risk factors of PAD and you must not wait until the symptoms appear. If you don’t have any symptoms you must go and check for PAD.


The most important cause of left leg numbness is peripheral artery disease. Peripheral artery disease is caused by the decreased blood flow due to the formation of blood clots which can lead to leg pain and death of tissue.

The most important risk factors are aging, smoking, and diabetes. The major complication of PAD is a heart attack (decreased blood flow to the heart results in ischemia of the heart muscle). Diagnosis of PAD depends on CT, MRI, and ABI. The treatment includes medication to treat high blood pressure, high cholesterol levels, and smoking cessation. PAD can be prevented by physical activity and low fat diet.


  1. ‘Leg Pain’. The Pain Center, https://www.thepaincenter.com/conditions/leg-pain/.
  2. Zemaitis, Michael R., et al. ‘Peripheral Arterial Disease’. StatPearls, StatPearls Publishing, 2022. PubMed, http://www.ncbi.nlm.nih.gov/books/NBK430745/.
  3. Symptoms and Diagnosis of PAD’. Www.Heart.Org, https://www.heart.org/en/health-topics/peripheral-artery-disease/symptoms-and-diagnosis-of-
  4. Understand Your Risk for PAD’. Www.Heart.Org, https://www.heart.org/en/health-topics/peripheral-artery-disease/understand-your-risk-for-pad.
  5. ‘What Is a Heart Attack?’ Www.Heart.Org, https://www.heart.org/en/health-topics/heart-attack/about-heart-attacks
  6. Symptoms and Diagnosis of PAD’. Www.Heart.Org, https://www.heart.org/en/health-topics/peripheral-artery-disease/symptoms-and-diagnosis-of-pad
  7. Prevention and Treatment of PAD’. www.Heart.Org, https://www.heart.org/en/health-topics/peripheral-artery-disease/prevention-and-treatment-of-pad.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Malaz Ameer Ata Almanan

Medical Student - University of Bahri, Khartoum, Sudan

Malaz Ameer Ata Almanan Mohammed. 4th year medical student. Researcher enthusiast. Passionate about ophthalmic surgery. I would like to be ophthalmologist.

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