Prof. Dr. Mehmet Şenoğlu — Brain, Nerve and Spine Surgery
A significant proportion of the patients who come to my office open with the same sentence: “Doctor, my left hand goes numb. I looked it up online and they say it’s a heart attack. I got very frightened.” I understand this fear; the association between “the left arm” and “a heart attack” is so firmly established in the public mind that even the slightest tingling in the left hand plants a seed of dread.
In this article, as a brain and nerve surgeon, I want to explain this subject to you as clearly as possible. Because there are two kinds of mistake here, and both are harmful: the first is taking every instance of numbness for a heart attack and living in needless panic. The second — and this is the more dangerous one — is brushing off a genuine heart attack symptom as “just a pinched nerve.”
Let me give you the most important piece of information first: numbness of the fingers on its own, lasting for days or weeks, is not a typical sign of a heart attack. However, if this numbness started suddenly and is accompanied by symptoms such as chest pain, shortness of breath, or cold sweating, the situation is entirely different and no time should be lost.
Let us now unpack this distinction step by step.
First, the Emergency: Symptoms for Which You Should Call Emergency Services Immediately
I would ask you to read this section before reading the rest of the article. If one of the pictures below is present, do not wait, do not go researching — call 112 (emergency services):
A picture suggesting a heart attack:
- Pressure, tightness, heaviness, or a sense of “an elephant sitting” on the middle of the chest — one that does not change with breathing or with movement
- The spreading of this sensation to the jaw, neck, shoulder, back, or left arm
- Cold sweating, paleness
- Shortness of breath
- Nausea, vomiting, a burning sensation in the stomach area
- Dizziness, feeling faint, sudden weakness
A picture suggesting a stroke:
- Numbness or loss of strength starting suddenly on one side of the body
- The mouth pulling to one side, drooping on one half of the face
- Speech impairment, being unable to find words, being unable to understand what is said
- Sudden loss of vision, loss of balance, a very severe and sudden headache
With these symptoms, time is muscle. Waiting and thinking “maybe it will pass” can lead to irreversible damage in the heart and the brain.
Are the Sensation in a Heart Attack and Nerve Numbness the Same Thing?
No, and the difference between them is more marked than most of my patients think.
A heart-related complaint is generally not so much “numbness” as a pain, pressure, heaviness, or spreading discomfort. It spreads down along the inner surface of the left arm, is not confined to specific fingers, and its borders are blurred. It is almost always accompanied by other symptoms: chest pressure, shortness of breath, cold sweating. It is typical for it to increase during exertion (climbing stairs, walking) and to decrease with rest.
Nerve-related numbness, on the other hand, is much more “mapped.” It settles into specific fingers, is of a tingling or pins-and-needles character, and changes with the position of the neck or the hand. It generally develops slowly over days to weeks and occurs on its own.
I summarize this to my patients like so: nerve problems ask “which finger?”; heart problems ask “what else is there?”
Even so, I must be honest here: in medicine there are exceptions. Especially in people with diabetes, in the elderly, and in women, a heart attack can run its course without typical chest pain, with only fatigue, shortness of breath, or a vague discomfort radiating into the arm. For this reason, being evaluated when you have doubts is always the safest path.
What Are the Real Causes of Numbness in the Left Hand and Fingers?
In my clinic, in the great majority of patients who come with left hand numbness, the cause is not the heart but the nervous system. The ones I encounter most often:
Carpal Tunnel Syndrome
This is the compression of the median nerve at the wrist, and it is the most common cause of hand numbness. It typically affects the thumb, index finger, middle finger, and the thumb side of the ring finger. Its most characteristic feature: it increases at night, wakes the patient from sleep, and eases when the hand is shaken. As it progresses, difficulty opening jars and dropping things from the hand begin.
Cubital Tunnel Syndrome (Ulnar Nerve Compression at the Elbow)
This is the compression of the ulnar nerve on the inner side of the elbow. It affects the ring and little fingers. It increases with keeping the elbow bent for long periods (talking on the phone, resting the elbow on a desk).
Cervical Disc Herniation (Cervical Radiculopathy)
When the disc in the neck presses on a nerve root, the numbness spreads from the neck to the shoulder, the arm, and the fingers. Which fingers are numb indicates which level is affected. It is typical for it to increase with neck movement and with coughing and sneezing.
Thoracic Outlet Syndrome
This is the compression of the vessel–nerve bundle in the narrow passage between the neck and the armpit. It causes numbness and weakness that increase when the arm is raised.
Systemic Causes
- Diabetes: Uncontrolled blood sugar wears down the nerves and generally causes symmetrical numbness in both hands and the feet.
- Vitamin B12 deficiency: It is critical for nerve health; its deficiency leads to widespread numbness.
- Thyroid conditions, kidney conditions, certain medications.
- Circulatory problems and Raynaud’s phenomenon: In the cold, the fingers change color and go numb.
Simple and Temporary Causes
Lying on the arm, staying in the same position for a long time, a narrow bag strap… In these, the numbness passes within minutes and requires no worry.
Why Does It Being the “Left Hand” Frighten People So Much?
Because in a heart attack, the place the pain most often radiates to really is the left arm. This is correct information. However, an important logical error is being made here:
The sentence “in a heart attack, pain can radiate to the left arm” does not mean “everyone whose left arm goes numb is having a heart attack.”
I explain it to my patients like this: most people with the flu get a headache; but not everyone with a headache has the flu. Statistically, the cause of left hand numbness is, in the overwhelming majority, nerve-related.
Let me also add this: a heart attack can also radiate to the right arm, the jaw, the back, or the stomach. So being on the “left” is not the sole determining factor; the real determining factor is the accompanying symptoms.
How Is the Diagnosis Made?
A correct diagnosis begins with asking the right questions. When evaluating a patient, I try to learn the following:
- Which fingers is the numbness in? (This alone is very informative.)
- When did it start, and did it develop suddenly or slowly?
- When does it increase: at night, during exertion, with neck movement?
- Is there anything accompanying it: chest pressure, shortness of breath, loss of strength?
- Is there a known condition such as diabetes, a thyroid problem, or anemia?
Then a neurological examination is performed. When needed:
- EMG (electromyography): It shows where and how much the nerve is compressed; it is the most valuable test in nerve compressions.
- Cervical MRI: When a herniation or nerve compression is suspected.
- Blood tests: For the assessment of blood sugar, B12, and thyroid function.
- Cardiac evaluation (ECG, cardiology consultation): If the complaint is related to exertion, if chest symptoms accompany it, or if there are risk factors.
Let me note an important point here: if there is doubt, the heart is ruled out first. As a brain surgeon, I do not hesitate to refer to cardiology the patients I deem appropriate. Because a pinched nerve can wait; a heart attack cannot.
Which Department Should I Go To?
- If there is chest pain, shortness of breath, or cold sweating, or if the numbness started suddenly: straight to the emergency department — or call 112.
- If the numbness has lasted for days/weeks, is in specific fingers, and occurs on its own: you can go to Neurology, Neurosurgery (Brain and Nerve Surgery), or Physical Medicine and Rehabilitation.
- If it appears with exertion and passes with rest: Cardiology first.
- If you have diabetes or if a general tiredness and weakness accompany it: Internal Medicine is a good starting point.
I would also like to remind you that going to neurosurgery does not necessarily mean surgery; the great majority of nerve compressions are managed with non-surgical methods.
Treatment in Nerve-Related Numbness
If the cause is a nerve compression, the treatment generally follows these steps:
- Use of a splint: In carpal tunnel, a night wrist splint is very effective.
- Activity and ergonomic adjustment: Keeping the wrist in a neutral position, not resting the elbow on a hard surface, bringing the screen to eye level, taking breaks.
- Medication and, when needed, local injection.
- Physical therapy and nerve-gliding exercises.
- Treating the underlying cause: Blood sugar control, correcting B12 deficiency, thyroid treatment.
- Surgery: It only comes onto the agenda when these methods prove insufficient, or if there is progressive loss of strength and muscle wasting.
Let me underline this: if there is thinning in the hand (muscle wasting) or steadily increasing loss of strength, one should not say, “Let’s wait a little longer.” 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.
Is numbness in the left hand and fingers a sign of a heart attack?
On its own, numbness that has been going on for a long time and settles into specific fingers is generally not a sign of a heart attack; its most common cause is nerve compressions. However, if the numbness is accompanied by chest pressure, shortness of breath, cold sweating, nausea, or pain radiating to the jaw or back, this is an emergency and 112 should be called immediately.
What is the arm numbness in a heart attack like?
A heart-related complaint is generally not a clear-cut “numbness” so much as pain, heaviness, or a sense of pressure spreading down the inner surface of the left arm. It is not confined to specific fingers, its borders are blurred, and chest symptoms almost always accompany it. It is typical for it to increase during exertion and decrease with rest.
Should I worry if only my left hand goes numb?
The numbness being on the left side is not by itself determining; a heart attack can also radiate to the right arm, the jaw, the back, or the stomach. What is really determining is the accompanying symptoms and the character of the numbness. Even so, any numbness that lasts a long time, recurs, or steadily increases should be evaluated.
What is the most common cause of numbness in the left hand and fingers?
The cause I encounter most often in my clinic is carpal tunnel syndrome (compression of the median nerve at the wrist). It is followed by ulnar nerve compression at the elbow, cervical disc herniation, thoracic outlet syndrome, and systemic causes such as diabetes and B12 deficiency.
What does hand numbness that increases at night indicate?
Numbness that increases at night, wakes the patient from sleep, and eases when the hand is shaken is the most typical feature of carpal tunnel syndrome. Heart attack symptoms do not show this kind of “eases when shaken” characteristic.
Can a cervical disc herniation cause left hand numbness?
Yes. When the disc in the neck presses on a nerve root, the numbness can spread from the neck to the shoulder, the arm, and the fingers. Which fingers are affected indicates which level is responsible. It is typical for it to increase with neck movement and with coughing.
Which department should one go to for hand numbness?
If chest symptoms accompany it, one should go to the emergency department or to cardiology. If the numbness occurs on its own and is in specific fingers, Neurology, Neurosurgery, or Physical Medicine and Rehabilitation are the appropriate departments. If you have diabetes, Internal Medicine is also a good starting point.
Does hand numbness go away on its own?
Numbness due to simple causes such as sleeping in the wrong position passes within minutes. However, it is not right to wait for numbness that has continued for days, recurs, or steadily increases to pass on its own; the underlying cause should be identified and treated.
Disclaimer (Legal Notice)
The information contained in this article has been prepared for general informational purposes only and in no way replaces a medical examination, diagnosis, or treatment. The cause of numbness in the hand and fingers, the appropriate treatment, and the necessary investigations vary greatly from person to person and can only be determined by a doctor who evaluates you. This article is not a guide for you to assess emergencies such as a heart attack or a stroke on your own. If symptoms such as chest pain, shortness of breath, cold sweating, suddenly starting one-sided loss of strength, speech impairment, or drooping of the face are present, call 112 (emergency services) or go to the nearest emergency department without losing any time.