The word 'neuropathy' is the medical term for damage to nerves, and diabetic neuropathy describes damage to nerves caused by diabetes, which is where the body is unable to maintain the correct levels of glucose in the blood.
Around 50% of all people with diabetes will develop diabetic neuropathy at some point. Although there is no specific cure for the condition, it can be managed so that symptoms and potential complications are minimised.
Diabetic neuropathy is categorised into four broad types…
- Peripheral (also referred to as 'distal symmetric peripheral neuropathy') – this describes neuropathy that affects the extremities, most commonly the legs and feet, but also sometimes the hands and arms.
- Autonomic – the autonomic nervous system controls the organs in the body.
- Focal (also referred to as 'mononeuropathy') – this is where specific individual nerves are affected, commonly in the head, torso, legs and hands.
- Proximal (also referred to as 'diabetic polyradiculopathy' or 'diabetic amyotrophy') – this type affects nerves in the hips, buttocks or thighs and generally affects only one side of the body, although it can spread from one side to the other; it is fairly rare.
High blood glucose levels and high levels of fats (triglycerides) in the blood, which are a feature of diabetes, damage nerves and the walls of small blood vessels that supply nutrients and oxygen to these nerves. This in turn impairs the ability of the nerves to communicate properly between their specific parts of the body and the brain.
People who are aware they are diabetic will ordinarily have been advised by their doctors of the risk of diabetic neuropathy, however a large number of people are either diabetic or pre-diabetic and are unaware of this. Known risk factors for developing diabetic neuropathy include…
- Being overweight or obese.
- Smoking (due to narrowing of arteries and constriction of blood flow).
- Kidney disease (due to resultant toxins entering the bloodstream).
- How long someone has been diabetic (the longer, the greater risk of developing diabetic neuropathy).
- Uncontrolled blood sugar levels.
In its early stages, diabetic neuropathy may not cause any noticeable symptoms at all. Symptoms when they do appear, are different depending on the type of neuropathy.
Peripheral diabetic neuropathy is the most common type. Common symptoms include…
- Pins and needles – a tingling and/or burning sensation.
- Pain – often sharp.
- Heightened sensitivity to touch.
- Weakness in the affected legs / feet / arms / hands.
- Balance issues.
- Loss of feeling in the feet.
- Conditions affecting the feet, for example ulceration, infection, pain in the joints and / or bones.
These symptoms tend to get worse during the night, and also tend to affect the legs and feet before spreading to the arms and hands.
Symptoms of autonomic diabetic neuropathy are related to dysfunction of one or more organs or bodily functions, due to internal nerve communication being compromised. Symptoms may include…
- Issues with the bladder and / or bowels.
- Issues with the gastrointestinal tract, often gastroparesis where the stomach empties slowly or nausea / vomiting / appetite loss.
- Eye issues, often where the eyes have difficulty adjusting to different light levels.
- Issues with sexual response.
Focal diabetic neuropathy is further subdivided into cranial and peripheral types. Common symptoms include…
- Eye problems, for example aching pain behind an eye, difficulty focusing or double vision.
- Bell's Palsy – where one side of the face is paralysed.
- Pins and needles/tingling in the hands and fingers (which does not affect the little fingers) .
- Weakness in the hands and fingers and loss of fine motor control.
- Carpal tunnel syndrome (compression of the nerve in the wrist which causes RSI) .
Symptoms of proximal diabetic neuropathy generally affect the thighs, hips, buttocks and legs, but can also affect the chest and abdomen. These symptoms are generally confined to one side of the body, but can spread to the other. Symptoms may include…
- Stomach pain (often severe).
- Difficulty getting out of a seat.
- Severe pain in one hip/thigh/buttock (generally on the same side).
- Weakness in the thighs (due to shrinkage in the thigh muscles).
Tests / Diagnosis
Diagnosis of diabetic neuropathy generally involves a review of medical history and thorough medical examination. Other test may be required to eliminate other causes of symptoms, for example low levels of thiamine and/or vitamin B1.