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.
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.
Sleeping Position
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
People with carpal tunnel syndrome may find that their wrists, hands, or arms fall asleep at night. For some people, nighttime paresthesia is the first sign of 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. Some people are more likely to develop carpal tunnel syndrome, including:
- Women and people assigned female at birth
- People who do repetitive work with their hands
- People with prior wrist injuries
- Relatives of people with carpal tunnel syndrome
- Individuals with certain health conditions, including diabetes or rheumatoid arthritis
In the condition’s early stages, paresthesia 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.
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Vitamin Deficiencies
Arms falling asleep at night can also be caused by deficiencies of certain vitamins, such as:
- Vitamin B1
- Vitamin B6
- Vitamin B12
- Folate (vitamin B9)
In addition to paresthesia, deficiencies of vitamin B12 or folate are associated with sleep disorders like restless legs syndrome.
Common reasons for a vitamin B12 or folate deficiency include:
- Eating a diet that includes few or no animal products
- Digestive conditions that make it harder to absorb certain nutrients
- Pregnancy
- Gastric bypass surgery
- Medications that prevent the body from absorbing or metabolizing vitamins
People concerned about a vitamin deficiency should contact their doctor before taking any dietary supplements. Large or frequent doses of certain vitamins can also cause numbness and tingling in the extremities.
Peripheral Neuropathy
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:
- Injuries
- Cancer or cancer treatment
- Infections
- Autoimmune disorders
- Liver or kidney disease
- Certain genetic conditions
However, the most common reason for developing peripheral neuropathy is diabetes.
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.
Other Causes
There are other potential causes of paresthesia, but they are less common, and some of them are very rare. These may include:
- Tumors that compress a nerve
- A herniated disc
- Inadequate circulation
- Shingles
- Migraines
- Multiple sclerosis
- Thyroid problems
- Animal or insect bites
- Stroke
- Certain medications
- Exposure to certain toxic substances or heavy metals
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:
- Confusion
- Loss of consciousness
- Difficulty walking or talking
- Weakness or inability to move
- Loss of control of your bowels or bladder
References
About The Author
Staff Writer, Sleep Health
With a bachelor’s degree in anthropology from Indiana University Bloomington, Rebecca enjoys making accurate, up-to-date health information accessible to all readers. As a freelance writer and editor, she has covered everything from healthcare and experimental music to education. Rebecca lives in Tennessee, where she spends her free time reading, writing fiction, and making music.
- Position: Side sleeper
- Temperature: Cold Sleeper
- Chronotype: Dolphin
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