You’ve likely experienced the sensation at least once — numbness or a pins-and-needles feeling of tingling in the arm, leg, hand, or foot when you stay in one position for too long. This feeling is called paresthesia and it’s actually quite common.
While most people occasionally find that an arm or another limb has “fallen asleep,” sometimes paresthesia can get worse at night or become a persistent problem. Frequent nighttime paresthesia is associated with sleep loss and may be a sign of an underlying health issue.
We look at some common causes of arms falling asleep at night, tips for preventing this experience, and when you should contact a doctor.
- Numbness at night is most commonly caused by excess pressure on limbs.
- Changing sleeping positions can often alleviate arm numbness.
- Conditions like carpal tunnel syndrome, vitamin deficiencies, and diabetes can cause numb sensations.
- If arm numbness is accompanied by other symptoms, talk to your doctor about diagnosis and treatment.
What Causes Arms to Fall Asleep at Night?
Having an arm fall asleep, and that prickly, tingling feeling when it wakes up, is often the result of pressure being put on a nerve. Nerves send signals between the brain, spinal cord, and other parts of the body, controlling a person’s vital signs, movements, and sensations.
When a person holds the same position for a long time, it can put pressure on a nerve and interfere with the nerve’s ability to send signals to the brain. The feeling of a limb falling asleep usually goes away when the person moves and relieves the pressure.
While pressure on a nerve is the most common cause of nerve issues in the arms, numbness and tingling can also develop due to other conditions that affect the arm’s nerves or the blood supply to the nerves.
Some evidence suggests that certain sleeping positions may increase the chances of a person’s arms falling asleep at night. Positions that can put pressure on nerves in the arms include:
- Laying on the stomach with the hands above the head
- Arms lifted away from the sides
- Elbows extended
- Forearms rotated with the hands facing up
- Flexed wrists
Carpal Tunnel Syndrome
Carpal tunnel syndrome happens when a nerve becomes squeezed as it runs from the forearm and into the hand. Compression in this nerve can feel like the hand and wrist have fallen asleep, causing numbness, weakness, or pain.
Carpal tunnel syndrome is a common condition that affects up to 5% of people. People who do repetitive work with their hands or with prior wrist injuries are more likely to develop carpal tunnel syndrome
In the condition’s early stages, nighttime paresthesia is the first sign of carpal tunnel syndrome and can cause a person to wake up in the middle of the night, especially when people sleep with their wrists bent. Fortunately, carpal tunnel syndrome is treatable, especially when it is diagnosed early. Common treatments include wearing splints on the wrist at night and medications. Severe cases may require surgery.
Arms falling asleep at night can also be caused by deficiencies of B vitamins.
In addition to paresthesia, deficiencies of vitamin B12 or folate are associated with sleep disorders like restless legs syndrome. Diet and medications can also lead to vitamin B12 or folate deficiency.
People concerned about a vitamin deficiency should contact their doctor before taking any dietary supplements or changing their medication regimen. Large or frequent doses of certain vitamins can also cause numbness and tingling in the extremities.
Peripheral neuropathy is a term used to describe different conditions that involve damage to the peripheral nerves, including the nerves that run down the arms and legs. The symptoms of peripheral neuropathy vary, depending on which nerves are affected. Damage to sensory nerves, which transmit signals related to touch, temperature, and pain, can lead to paresthesia in the limbs.
Conditions that may cause nerve damage and peripheral neuropathy include:
- Cancer or cancer treatment
- Autoimmune disorders
- Liver or kidney disease
- Certain genetic conditions
There are other potential causes of paresthesia, but they are less common, and some of them are very rare. However, the most common reason for developing peripheral neuropathy is diabetes.
Over half of all people with diabetes experience diabetic neuropathy. Diabetic neuropathy develops when high blood sugar levels caused by diabetes damages nerves and blood vessels over time. Symptoms of diabetic neuropathy include numbness and tingling in the feet, legs, arms, or hands. These symptoms often become worse at night.
Detecting diabetic neuropathy early is important to prevent complications. Additional symptoms of diabetic neuropathy include:
- Sharp pains or a burning sensation in the extremities
- Nausea or vomiting
- Constipation or diarrhea
- Urinary issues
- Feeling dizzy when changing positions
The longer a person has diabetes, the more likely they are to develop neuropathy. However, diabetic neuropathy can be prevented or managed by keeping a person’s blood sugar under control.
How to Prevent Your Arms From Falling Asleep at Night
Treatments for paresthesia depend on what is causing the limbs to fall asleep. Several tips may help you reduce or prevent how often your arms fall asleep at night.
- Change Your Sleeping Position: Avoid sleeping in positions that exacerbate numbness or tingling, like sleeping with your wrists flexed. If you usually sleep on your stomach or back, try sleeping on your side. If necessary, wear a splint to bed to keep your wrists in a neutral position at night to minimize the symptoms of carpal tunnel syndrome.
- Maintain Healthy Blood Sugar Levels: People who have high blood sugar for long periods of time are more likely to develop diabetic neuropathy. Keeping blood sugar levels in check may prevent nerve damage from developing or becoming worse.
- Maintain a Healthy Weight: Some evidence suggests that individuals with a higher body mass index (BMI) may be more prone to nighttime paresthesia. People who have obesity are also at higher risk of developing diabetic neuropathy and carpal tunnel syndrome.
When You Should Seek Medical Help
If your arms are frequently falling asleep or paresthesia is keeping you awake at night, it’s important to talk to your doctor. A doctor can determine why your arms fall asleep at night and suggest appropriate treatments.
In some instances, numbness and tingling may signal a medical emergency. Get immediate medical attention if you experience paresthesia after injuring your back, neck, or head, or if you are also having symptoms such as:
- Loss of consciousness
- Difficulty walking or talking
- Weakness or inability to move
- Loss of control of your bowels or bladder
Ask the Sleep Doctor
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