Condition. Paresthesia

What is Paresthesia?

Paresthesia and the loss of sensation in a specific body area are two of the most frequently noted disturbances in sensation. The paresthesia definition refers to a burning or prickling sensation usually felt in the hands, arms, legs, or feet and can also occur in other parts of the body. The sensation is typically painless and described as tingling or numbness, skin crawling, or itching. The manifestation of paresthesia may be transient or chronic and may have dozens of possible underlying causes.

Types of Paresthesia

• One of the most common types of paresthesia is the feeling as if a part of the body is “asleep” or the feeling of “pins and needles”.
• Another relatively common paresthesia is “formication.” This is the feeling of having bugs or insects crawling over and/or under the skin.

Paresthesia is described as a sensation of burning, pricking, prickling, creeping, or tickling on the skin without a cause. It is most often related to irritation or injury of a nerve root or a sensory nerve. Paresthesia might come and go, or it may be chronic. It is not always possible to determine the cause of paresthesia. Temporary paresthesia often happens because of pressure on a nerve or brief periods of poor circulation. This can occur when you fall asleep on your hand or sit with your legs crossed for too long. Chronic paresthesia may be a sign of nerve damage. Two types of nerve damage are radiculopathy and neuropathy. 

• Radiculopathy is when nerve roots become compressed, irritated, or inflamed. This can occur when you have a herniated disk that presses on a nerve, a narrowing of the canal that transmits the nerve from your spinal cord to your extremity, any mass that compresses the nerve as it exits the spinal column.
• Neuropathy, on the other hand, occurs due to chronic nerve damage. The most common cause of neuropathy is hyperglycemia.

Causes of Paresthesia

Chronic paresthesia is often a symptom of an underlying neurological disease or traumatic nerve damage. Disorders affecting the central nervous system may cause paresthesia. Such disorders include:

• Stroke and transient ischemic attacks (mini-strokes) wherein blood flow to the brain is cut off and causes damage.
• Multiple sclerosis, transverse myelitis, and encephalitis are diseases of the central nervous system that affect how your body feels. 
• A tumor or vascular lesion pressed up against the brain, or spinal cord can also cause paresthesia.
• Nerve entrapment syndromes, such as carpal tunnel syndrome.
• Sciatica can damage and cause pressure to the peripheral nerves that cause paresthesia accompanied by pain. 
• Diabetes mellitus is a blood sugar disorder that damages the nerves over time.
• Lack of some vitamins, especially low levels of vitamin B12, can also cause numbness sensations.
• Certain medications such as some types of chemotherapy, antibiotics, and anti-seizure medications that cause nerve irritation or damage can eventually cause paresthesia.