Tingling in hands and feet
Tingling in the hands, feet or both is an extremely common and bothersome symptom. Such tingling can sometimes be benign and temporary. For example, it could be the result of sustained pressure on nerves when your arm is crooked under your head as you fall asleep. Or it could be from sustained pressure on nerves when crossing your legs for too long. In either case, the "pins and needles" effect - which is usually painless - is soon relieved by removing the pressure that caused it.
In many cases, however, tingling in the hands, feet or both can be severe, episodic or chronic. It also can accompany other symptoms such as pain, itching, numbness and muscle wasting. In such cases tingling may be a sign of nerve damage, which can result from causes as varied as traumatic injuries or repetitive stress injuries, bacterial or viral infections, toxic exposures, and systemic diseases such as diabetes.
Such nerve damage is known as peripheral neuropathy because it affects nerves distant from the brain and spinal cord, often in the hands and feet. There are more than 100 different types of peripheral neuropathy. Over time, peripheral neuropathy can worsen, resulting in decreased mobility and even disability. In England about one in 50 people have peripheral neuropathy, with approximately 8% of people 55 years old and over experiencing the condition.
It's important to seek prompt medical evaluation for any persistent tingling in your hands, feet or both. The earlier the underlying cause of your tingling is identified and brought under control, the less likely you are to suffer potentially lifelong consequences.
Causes of tingling in the hands and feet
Diabetes is one of the most common causes of peripheral neuropathy in England. Between 10% and 20% of people recently diagnosed with diabetes will have a peripheral neuropathy, called peripheral polyneuropathy. In diabetic polyneuropathy, tingling and other symptoms often first develop in both feet and ascend the legs, followed by tingling and other symptoms that affect both hands and ascend the arms. People with diabetes have mild to severe forms of nerve damage. In many cases, these symptoms are the first signs of diabetes.
In a number of peripheral neuropathy cases, the cause is unknown or "idiopathic." However, there are a variety of conditions that cause the condition such as:
Nerve entrapment syndromes. These include carpal tunnel syndrome, ulnar nerve palsy, peroneal nerve palsy and radial nerve palsy.
Systemic diseases. These include kidney disorders, liver disease, vascular damage and blood diseases, amyloidosis, connective tissue disorders and chronic inflammation, hormonal imbalances (including hypothyroidism), and cancers and benign tumours that impinge on nerves.
Vitamin deficiencies. Vitamins E, B1, B6, B12 and niacin are essential for healthy nerve function. A B12 deficiency, for example, can lead to pernicious anaemia, an important cause of peripheral neuropathy. However, too much B6 can also cause tingling in the hands and feet.