I Have Numbness in My Leg — Which Department Should I Go To?

Prof. Dr. Mehmet Şenoğlu — Brain, Nerve and Spine Surgery

Numbness in the leg is one of the complaints I hear most often in my office. However, the real difficulty people experience with this complaint is most of the time not the numbness itself, but not knowing where to go. Neurology? Neurosurgery? Vascular surgery? Internal medicine?

This indecision is understandable, because leg numbness really can have many different causes. But I have good news for you: finding the right department is easier than you think. Because the character of your numbness shows you the way.

In this article, I will first explain which symptoms point to which system, and then, accordingly, which department you should go to, step by step.

First, the Emergency: Symptoms for Which You Should Go Straight to the Emergency Department

I would ask you to read this section before reading the rest of the article. If one of the following is present, do not wait for an appointment — go directly to the nearest emergency department:

• Losing control of urine or stool, incontinence (cauda equina syndrome — a surgical emergency)
• “Saddle-shaped” loss of sensation in the anal region, the buttocks, and the inner thighs
• Numbness and weakness starting suddenly in both legs at once
• Suddenly starting, rapidly progressing marked loss of strength in the leg (being unable to lift the foot)
• The leg suddenly becoming cold, turning pale or bluish, the pulse being absent, with severe pain (acute arterial blockage — a vascular emergency)
• Sudden swelling, redness, and warmth in one leg (suspicion of deep vein thrombosis)
• Sudden numbness on one side of the body, the mouth pulling to one side, speech impairment (suspicion of a stroke — call 112 immediately)

In these pictures, time means tissue. Do not wait.

What Is Your Numbness Telling You? Three Basic Forks in the Road

We can broadly divide the causes of leg numbness into three groups. Each has its own characteristic “signature.”

1) Nerve-Related Numbness (The Most Common Group)

How is it recognized?

• The numbness starts in the lower back and spreads to the buttock, the leg, and the foot
• It is generally one-sided
• It increases with coughing, sneezing, and bending forward
• It is of a burning, tingling, electric-shock character
• It settles into a specific “strip” (for example the back of the leg or its outer edge)

Possible causes: Lumbar disc herniation (the most common), lumbar canal stenosis, spondylolisthesis, piriformis syndrome.

Canal stenosis has a very typical sign: numbness and pain radiating into the legs the more one walks, which passes on sitting down or bending forward. My patients usually describe this as “I feel better when I lean on the shopping cart.”

2) Metabolic / Systemic Numbness

How is it recognized?

• Symmetrical in both legs
• Starting in the toes and progressing upward (a “stocking-like” distribution)
• Increasing at night, of a burning character
• No relationship to the lower back at all

Possible causes: Diabetic neuropathy (the most common), vitamin B12 deficiency, thyroid conditions, kidney failure, certain medications, excessive alcohol use.

3) Vascular Numbness

How is it recognized?

• It appears with walking and passes on stopping and resting (claudication)
• The leg and foot are cold, pale in color
• The foot pulses are weak or absent
• A non-healing wound on the foot, changes in the nails and hair
• A history of smoking, high blood pressure, high cholesterol, and diabetes often accompanies it

Possible causes: Peripheral arterial disease (blockage of the leg arteries), deep vein thrombosis.

An important distinction: Both canal stenosis and arterial blockage cause “leg symptoms that increase with walking.” The difference is this: in canal stenosis, bending forward brings relief; in vascular disease, simply stopping is enough.

So, Which Department Should I Go To?

Now let us move on to the practical answer. Read the guidance below according to your own situation.

Neurosurgery (Brain and Nerve Surgery) — When?

• If the numbness spreads from the lower back down into the leg
• If low back/leg pain accompanies it
• If a lumbar disc herniation, canal stenosis, or spondylolisthesis has been found on your MRI
• If there is loss of strength (the foot dragging, foot drop)
• If the complaints do not go away despite physical therapy

Here I must certainly emphasize: going to neurosurgery does not mean you are going to have surgery. Roughly 80–90% of lumbar disc herniations resolve without surgery. Our real job is to distinguish which finding requires follow-up, which requires treatment, and which requires surgery.

Neurology — When?

• If the numbness is in both legs and symmetrical
• If it starts in the feet and progresses upward
• If it has no relationship to the lower back
• If you have a known neurological condition
• If there are additional findings such as impaired balance, tremor, or muscle twitching

Neurology assesses the nervous system as a whole and interprets tests such as EMG.

Physical Medicine and Rehabilitation (PM&R) — When?

• If the complaints are mild to moderate and have recently started
• If there is no loss of strength
• If a muscle-related problem is suspected
• If non-surgical treatment (exercise, physical therapy) is to be planned

For complaints arising from the lower back, PM&R is most of the time the most appropriate first step.

Cardiovascular Surgery — When?

• If the numbness appears with walking and passes with rest
• If the leg and foot are cold or have changed color
• If the foot pulses cannot be felt
• If there is a non-healing wound on the foot
• If there is sudden swelling and redness in the leg

Internal Medicine / Endocrinology — When?

• If you have diabetes or if diabetes is suspected
• If general complaints such as fatigue, weight change, or forgetfulness accompany the numbness
• If a systemic cause such as B12, thyroid, or kidney problems is suspected

What If You Are Not Sure?

If you are not sure which category to place yourself in, the most practical route is to go to your family doctor. Your family doctor performs the initial assessment, requests the basic blood tests (blood sugar, B12, thyroid), and directs you to the right department. This saves both time and the cost of unnecessary investigations.

Bring These With You to Your Appointment

To make the consultation productive, I recommend preparing the following:

• Your previous MRI, CT, and EMG results, if you have any (reports and, if possible, the CDs)
• A list of all the medications you use
• Your most recent blood tests
• And most importantly: the story of your complaint

Be prepared to tell your doctor clearly:

• When did the numbness start? Suddenly or gradually?
• Exactly where is it? (The calf, the sole of the foot, the outer thigh?)
• Is it one-sided or two-sided?
• When does it increase? While walking, while sitting, at night?
• What brings relief? Resting, or bending forward?
• Is there loss of strength? Do you struggle climbing stairs, does your foot drag?

The answers you give to these questions most often make up half of the diagnosis.

Which Tests Might Be Requested?

Although it varies according to the cause, the ones frequently used are:

• Neurological examination: The beginning of everything and the most valuable.
• Lumbar MRI: When a herniation, canal stenosis, or slippage is suspected.
• EMG (electromyography): It shows the location and degree of nerve damage.
• Blood tests: Blood sugar, HbA1c, B12, thyroid, kidney function.
• Color Doppler ultrasound and pulse examination: When a vascular cause is suspected.

Is It Right to Wait and Hope It Passes?

The answer to this question depends on the nature of your numbness.

Can wait: Numbness caused by crossing your legs or staying in the same position for a long time, which passes within minutes. These are innocent.

Should not wait: Numbness that has continued for days, recurs, is steadily increasing, or is spreading. Especially if loss of strength accompanies it.

I explain this to my patients like so: pain takes you to the doctor, but what is truly dangerous is the numbness and loss of strength that progress silently. Because a nerve that has been under compression for a long time may not fully return to its former function even if it is relieved with surgery. In nerve surgery, time directly affects the outcome.

Frequently Asked Questions

Below, I have gathered the most frequently asked questions on this subject along with brief answers. These answers are for general information; the information that applies to your specific situation is the one given by the doctor who examines you.

Which department should I go to for numbness in the leg?

If the numbness spreads from the lower back into the leg and is accompanied by pain, Neurosurgery or Physical Medicine and Rehabilitation; if it starts in both feet and progresses upward, Neurology; if it increases with walking and passes with rest and the foot is cold, Cardiovascular Surgery; if you have diabetes, Internal Medicine/Endocrinology are appropriate. If you are not sure, start with your family doctor.

What is the most common cause of leg numbness?

The most common causes are nerve compressions such as lumbar disc herniation and lumbar canal stenosis. These are followed by diabetic neuropathy, vitamin B12 deficiency, and arterial blockages.

How do I tell whether the numbness is nerve-related or vascular?

Nerve-related numbness generally spreads from the lower back, is of a burning-tingling character, and increases at night. Vascular numbness, on the other hand, appears with walking and passes with rest; the leg is cold and the pulses are weak. The definitive distinction is made with an examination and tests.

I have numbness in both legs at once — what does this mean?

Symmetrical, two-sided numbness starting in the feet generally suggests metabolic causes (diabetes, B12 deficiency, thyroid problems). However, lumbar canal stenosis can also cause two-sided numbness. Suddenly starting two-sided numbness and weakness, meanwhile, is an emergency; go to the emergency department immediately.

If I go to neurosurgery, will I have surgery?

No. Roughly 80–90% of lumbar disc herniations resolve without surgery. The most frequent job of neurosurgery is to distinguish which patient requires follow-up, which requires physical therapy, and which requires surgery.

Is leg numbness a sign of a lumbar disc herniation?

It can be; especially if the numbness spreads from the lower back to the buttock and the leg, is one-sided, and increases with coughing, a lumbar disc herniation comes to mind. However, numbness alone does not establish a diagnosis of a herniation; it should be assessed with an examination and, if needed, an MRI.

Does B12 deficiency cause numbness in the leg?

Yes. Vitamin B12 protects the sheath of the nerves; in its deficiency, symmetrical, burning-type numbness starting in the feet can be seen. It is detected with a simple blood test, and its treatment is generally straightforward. This is why B12 should always be checked in cases of numbness.

My numbness increases at night — what does this indicate?

Numbness that increases at night suggests nerve-related causes more — especially diabetic neuropathy and nerve compressions. Vascular complaints, by contrast, typically increase with walking. Even so, this is not a rule; you need to be assessed.

How long should I wait before going to a doctor?

For numbness due to simple causes such as crossing your legs, which passes within minutes, waiting is appropriate. However, do not lose time with numbness that has continued for days, recurs, or is increasing. If there is loss of strength, disruption of bladder-bowel control, or saddle-shaped loss of sensation, go to the emergency department without waiting.

Disclaimer (Legal Notice)

The information contained in this article has been prepared for general informational and guidance purposes only and in no way replaces a medical examination, diagnosis, or treatment. The cause of numbness in the leg, the appropriate investigations, and the treatment vary greatly from person to person and can only be determined by a doctor who evaluates you. This article is not a guide for diagnosing yourself; the departmental suggestions above are only guidance for a first point of contact. If emergency symptoms such as urinary/fecal incontinence, saddle-shaped loss of sensation, sudden and progressive loss of strength, sudden coldness or color change in the leg, or sudden one-sided numbness and speech impairment are present, go to the nearest emergency department without losing any time, or call 112.