A person’s arms may go numb while they sleep due to their sleeping posture. However, a numb arm at night may also result from underlying nerve damage.

When one or both arms seem to fall asleep, it can feel as if they are going numb. The medical term for this feeling is paresthesia. A variety of causes may be responsible. Some are benign, while others require treatment.

In this article, learn what can cause the feeling of the arms falling asleep at night, how to prevent the sensation, and what treatments are available.

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Paresthesia is a burning or prickling sensation that most commonly occurs in the limbs, hands, and feet.

People also tend to describe paresthesia as a feeling of pins and needles, crawling skin, or numbness. Another common description is that the area has fallen asleep.

Paresthesia can occur at any time, with no warning. While the sensation may be uncomfortable, it is usually painless.

Learn more about paraesthesia here.

People may experience occasional, brief episodes of paresthesia during sleep without realising it. Often, a person’s position is the cause. For example, the arm may fall asleep because a person is lying in a way that puts pressure on a nerve in the limb.

Cases of positional paresthesia are typically harmless and generally occur when a nerve is under sustained pressure. The sensation often goes away after a person changes positions.

The following medical conditions can also cause paresthesia in the arms:

Damage to nerves in the arm can cause localized feelings of numbness, tingling, or burning. The medical term for damage to nerves outside of the brain and spinal cord is peripheral neuropathy.

Many factors can cause nerve damage that results in a sensation of numbness in the arms, hands, legs, or feet.

Learn more about peripheral neuropathy here.

Carpal tunnel syndrome

Carpal tunnel syndrome is a common nerve disorder. It occurs when repetitive finger motion, like typing or playing the piano, puts too much pressure on the median nerve. This nerve runs the arm’s length and passes into the hand through the wrist.

The syndrome can cause pain and numbness in the arms and hands, but one of the first symptoms is paresthesia which occurs in the hands and wrists more frequently at night.

Learn more about carpal tunnel syndrome and its symptoms here.

Diabetic neuropathy

People with diabetes have a risk of nerve damage, and the medical term for this complication is diabetic neuropathy.

It occurs when high blood sugar levels and fats injure the nerve endings over time.

Diabetic neuropathy usually causes numbness and tingling in the feet and legs, though it can also affect the arms and hands.

Learn more about diabetic neuropathy here.

Numbness and tingling are some of the most common symptoms of multiple sclerosis (MS).

These symptoms usually affect the face. However, depending on the location of the spinal lesions that occur with multiple sclerosis, a person may also feel numbness and tingling in the arms or legs.

Learn all there is to know about MS in our dedicated hub.

Stroke and transient ischemic attacks can cause numbness and tingling in the arms. A transient ischemic attack occurs when something temporarily blocks blood flow to the brain.

Strokes and transient ischemic attacks can affect the functioning of the nerves, and they can cause changes in sensation, including paresthesia in the arms or legs, as well as heightened feelings of numbness or pain.

Learn more about cardiovascular health in our dedicated hub.

Certain lifestyle factors can increase a person’s risk of nerve compression, and ultimately numbness in the extremities. For example:

  • having a job that involves repetitive hand or arm motions
  • sleeping on one side
  • living with diabetes

Vitamin deficiency

Vitamin B deficiencies can cause a variety of problems, including anemia and tingling in the extremities. It can be easy to mistake this tingling sensation for the arms falling asleep.

People at an increased risk for vitamin B deficiencies include:

Learn more about the symptoms of a vitamin B-12 deficiency here.

Prevention and treatment of arm numbness during sleep will depend on its cause.

For example, a person may benefit from learning to sleep in a less restrictive position. If a person is at risk of carpal tunnel syndrome, it may help to wear a brace or do exercises.

Additionally, studies show that regular exercise can reduce the frequency of sleep paraesthesia in people with MS.

If a vitamin B deficiency is causing the sensation of the arms falling asleep, a doctor can prescribe supplements or recommend changes to the diet.

If a person notices this sensation frequently, they may require medical attention, especially if they also experience:

  • visual disturbances
  • facial numbness or tingling
  • difficulty speaking
  • difficulty with coordination, such as while walking
  • unexplained weakness or pain

Anyone who suspects their paresthesia results from an underlying medical condition, a medication, or alcohol use disorder should speak with a doctor.

It is common for the arms to fall asleep, especially at night, when a person may be lying in a position that places pressure on a nerve. However, numbness in the extremities can also result from nerve damage and other underlying medical conditions.

In cases of poor sleep posture numbness will subside independently. If a person experiences persistent numbness they should contact a healthcare professional to determine the cause and best treatment plan.