Neuropathy, also known as peripheral neuropathy, is a condition that causes numbness, pain, tingling and weakness, usually in the hands and feet. It may occur episodically or progress gradually over years. According to the Neuropathy Association (NA), 30 percent of cases evolve from diabetes, 30 percent from unknown causes and 40 percent from infections, autoimmune disorders, genetic factors, nutrient imbalances, tumors or toxins. Symptoms of neuropathy vary depending on type of neuropathy and which nerves are affected.
Neuropathy causes damage to fibers that affect physical sensation, which causes nerve pain, tingling and numbness. Sensory damage may reduce a person's ability to determine the position of his joints and suffer from poor coordination. According to the University of Maryland Medical Center (UMMC), sensation symptoms frequently start within the feet and gradually progress toward the body's center as neuropathy worsens. Though sensory symptoms are common among diabetes-related neuropathy, it affects other forms as well.
When neuropathy causes damage to fibers that affect a person's muscles, it can lead to physical weakness, loss of dexterity and reduced muscle mass. Muscle cramping or twitching, trouble swallowing or breathing, paralysis of affected body parts and reduced muscle control may also occur. According to the UMMC, these symptoms often lead to tripping, resultant injuries and difficulty executing tasks that require dexterity, such as buttoning a shirt, writing and opening jars and doors. Reduced nerve function in the hands may cause people to drop objects frequently. When leg muscles are weakened, people may struggle to run or walk or observe a sense of "heaviness" in the legs. Normally simple tasks such as climbing stairs may become challenging and lead to frustration and muscle cramps.
Neuropathy may also affect that autonomic nerves that contribute to involuntary functions, such as heartbeat, digestive processes, blood pressure and organ function. When this occurs, numerous symptoms may evolve, such as blurry vision, constipation or diarrhea, inability or reduced ability to sweat, abdominal bloating and difficulty during urination. According to the UMMC, fainting or dizziness upon standing may indicate a drop in blood pressure caused by autonomic neuropathy symptoms. People with neuropathy may become sensitive to heat during physical exertion, such as exercise. When the digestive system is affected, nausea or vomiting may occur after eating. Impotence in males and unintentional weight loss may also stem from these symptoms.