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What Causes Numbness on the Left Side?

Numbness on the left side can be a symptom of various conditions, from nerve compression to stroke. It's crucial to understand the underlying issues, as they can have significant health implications. Identifying the cause requires a careful look at lifestyle, medical history, and sometimes, immediate medical attention. Have you ever experienced such sensations? Learn what your body might be signaling.
Meshell Powell
Meshell Powell

A number of different medical problems can cause numbness on the left side, with some being more serious than others. Numbness that lasts more than a few moments should almost always be a cause for alarm, though, as should tingling that occurs over large parts of the body. Strokes, brain tumors, and seizures are some of the main causes of this sort of loss of sensation, but more latent conditions like multiple sclerosis or diabetes might also be responsible. People who regularly feel numb on their left side or who are unable to account for sudden or persistent tingling should usually seek medical attention.


A stroke may cause body numbness.
A stroke may cause body numbness.

One of the most common causes of numbness anywhere is stroke, which happens when the brain — in part or full — suddenly loses its blood supply. When this lasts for more than a few seconds, the results can be devastating and tend to be immediately noticeable. Smaller strokes can sometimes go undetected at first, though their symptoms and after-effects are usually very apparent. Numbness that is concentrated on one side of the body is often caused by a stroke impacting the part of the brain that controls that side.

Migraines may cause body numbness.
Migraines may cause body numbness.

The human brain is divided into hemispheres, with the right hemisphere controlling the left side of the body and vice versa. A stroke that impacted any of the major communication zones of the right hemisphere could cause numbness that a person would feel up and down his or her left side. This is particularly true of tingling that happens in multiple places simultaneously, like in an arm, a leg, and shoulder all at the same time.

Brain Tumors

Brain tumors may cause numbness on the left side.
Brain tumors may cause numbness on the left side.

A brain tumor in the right hemisphere can also cause a slow loss of sensation on the left side of the body, though in these cases the tingling tends to get progressively worse. What may start as intermittent numbness will progress to full loss of feeling. The sooner tumors are identified the better the likelihood that they can be safely removed or neutralized, which makes paying attention to sensation problems really important.

Seizures and Migraines

Inactivity may cause body numbness.
Inactivity may cause body numbness.

Migraine headaches and seizures are very different from a medical perspective, but both tend to “signal” or forewarn their arrival with symptoms that can include targeted numbness. Timing can vary from person to person, but in most cases numbness comes and goes with about an hour of either a debilitating headache or a brain seizure. It’s rare for this symptom to be long lasting, and treating the root cause usually takes care of it, too.


Multiple sclerosis can cause numbness in parts of the body, including the left side.
Multiple sclerosis can cause numbness in parts of the body, including the left side.

The blood sugar condition diabetes sometimes causes damage to the central nervous system, particularly when it has gone untreated for a long time. In some cases this damage can lead to numbness that is focused on certain body parts or even entire sides of the body. Patients can usually get rid of this by bringing their blood sugar levels back within normal range, but not always. Diabetics who experience persistent numbness or tingling should usually get a medical evaluation to figure out if their condition is being properly managed.

Multiple Sclerosis

People who suffer from multiple sclerosis sometimes also experience numbness that is concentrated in certain parts of their body. Most patients report tingling in single places, commonly the hands and feet, at first, but as the condition develops this can spread to entire sides of the body. Multiple sclerosis is a degenerative neurological condition where the protective coating around the body’s core nerves begins eroding over time. The disease can’t be cured, but a number of different medications and lifestyle changes can help patients keep their symptoms, including numbness, under control.


Sitting, standing, or lying in one position for prolonged periods of time can sometimes cause numbness on one side, too. People who have limited mobility or who work in vocations that require staying in one position a long time are usually the most at risk for this sort of numbness, and it’s also a common compliant of long-term care patients and others who are confined to bed for any length of time. Changing position and moving the impacted arm and leg can often help get the blood circulating again, which tends to help things feel normal again; people with mobility issues or who are bedridden for months at a time are usually wise to find caregivers who are able to help them move their muscles every now and then.

Treatment Options

Treating numbness on the left side usually requires a varied and somewhat dynamic approach, and typically centers on managing and treating the underlying condition. It is rare for entire areas of the body to lose sensation without some other problem. Sometimes tingling will go away on its own, as is often the case with inactivity, but medical providers usually recommend that anyone who experiences numbness that doesn’t go away, that comes and goes with some regularity, or that seems to get worse over time get help to uncover the root cause.

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Discussion Comments


I have persistent tingling from left shoulder going down the fingers. I have been to see my GP but he feels there is nothing to worry about. Sadly this has been going on for almost three months.

What should I do? I know something is not right but the "expert" says it is OK!


The left side of my left hand constantly goes numb.


I am experiencing numbness from mouth all the way down to feet on my left side.


My left eye has been tickling for about a month now. I didn't pay any attention to it, but yesterday my left foot felt numb and still my eye is tickling and I am getting worried because they are both on the left side. Can you give me an answer please?


I have numbness in my arm hand left side and left thigh. I have had blood work done and all results were negative, along with an X-ray of the neck area. Are there any other causes for numbness for the above?


I've been dizzy and nauseated since mid May. Then, I've had numbness on the left side of my body, and a super fast heart beat on and off during the day.

They originally said vertigo, but since it hasn't gone away yet, I've had three MRI's and lots of blood tests, to rule out multiple sclerosis. Now they are doing a spinal tap.

I'm not going to let them stop testing everything, until they find out why I'm still dizzy and nauseated every day. Go to a neurologist and get tested. Good luck!


Yesterday and today I had numbness in my left arm, hand and leg and also tingling in my left fingers. At the same time I was light headed, almost dizzy. I am still not okay. What can it be? Should I take some aspirin before I go to sleep?

Should I go to the emergency and get an MRI?


I think there was a case on the news recently where a person was experiencing numbness on the left side of his face and he twittered about it to try and get advice.

Someone replied to him and correctly diagnosed it. It was the start of a stroke and if the guy hadn't got help in time he might have died or suffered more serious complications than he did.

If you are feeling numbness in the left side of your body you should absolutely get help right away. If nothing else find someone to be with you, just in case, because if you have a serious stroke, getting help in time is the difference between life and death.


If you have a job or something which makes you rely more on one side than the other, even if it doesn't really cause numbness you should try to switch up the sides as much as possible.

My friend had a situation like that where he was planting trees all day and he got in the habit of using one arm and leg for one part of the job and the other side for different parts.

He started getting pain in one of his knees and couldn't work out what it was.

Eventually he went to see a physiotherapist and she explained that he'd strengthened one side of his body too much and it was causing him to walk funny and putting strain on his knee.

It's weird the way the body works.

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    • A stroke may cause body numbness.
      By: JPC-PROD
      A stroke may cause body numbness.
    • Migraines may cause body numbness.
      By: vbaleha
      Migraines may cause body numbness.
    • Brain tumors may cause numbness on the left side.
      By: Andrey Burmakin
      Brain tumors may cause numbness on the left side.
    • Inactivity may cause body numbness.
      By: Vasiliy Koval
      Inactivity may cause body numbness.
    • Multiple sclerosis can cause numbness in parts of the body, including the left side.
      By: designua
      Multiple sclerosis can cause numbness in parts of the body, including the left side.