When you have diabetes, nerve damage called diabetic neuropathy can happen due to high blood sugar. There are four main types of diabetic neuropathy. You may have just one type. Or you may have symptoms of more than one type. Most types of diabetic neuropathy develop over time. So you might not notice symptoms until lots of nerve damage has happened.

Talk with your healthcare professional if you have any of the symptoms noted below. If diabetic neuropathy is the cause, early treatment can help prevent more health issues.

Peripheral neuropathy is the most common type of diabetic neuropathy. It can affect nerves in the feet, legs, hands and arms. It often starts in the feet, usually affecting both feet at the same time. Most often, peripheral neuropathy symptoms affect both sides of the body.

The symptoms can include:

• Numbness or less ability to feel pain or temperature changes, especially in the feet and toes.
• A tingling or burning feeling.
• Sharp, jabbing pain that may be worse at night.
• Serious discomfort from touch. For some people, even the weight of a bedsheet can be painful.
• Muscle weakness.
• Loss of reflex response.
• Serious foot issues such as ulcers, infections, changes in foot shape, and bone and joint damage.

Autonomic neuropathy causes damage within a network of nerves that control the internal organs. This network is called the autonomic nervous system. It controls blood pressure, heart rate, and the sweat glands, eyes, bladder, digestive system and sex organs. Diabetes can affect the nerves in any of these areas. It can bring on symptoms including:

• A lack of awareness that blood sugar levels are low. This is called hypoglycemia unawareness.
• Bladder conditions. These can include frequent urinary tract infections. Some people lose bladder control, called urinary incontinence, or have trouble emptying the bladder, called urinary retention.
• Constipation, serious diarrhea or both.
• Slow emptying of the stomach, called gastroparesis. This can lead to upset stomach, vomiting, a feeling of fullness and loss of appetite.
• Trouble swallowing.
• Problems getting an erection or trouble ejaculating.
• Vaginal dryness, less feeling around the vagina, and trouble with sexual desire or orgasm.
• Sweating a lot, especially at night or during meals. Or less ability to sweat, even when hot.
• Drops in blood pressure when rising from sitting or lying down, called orthostatic hypotension. This may cause feelings of dizziness or fainting.
• Trouble controlling body temperature.
• Changes in the way the eyes adjust from light to dark or distance to nearness.
• Faster heartbeat even while at rest.

Proximal neuropathy affects nerves in the thighs, hips, buttocks or legs. This condition is more common in people who have type 2 diabetes and in those older than 50. Another name for it is diabetic polyradiculopathy.

Most often, proximal neuropathy symptoms happen on one side of the body. Sometimes they spread to the other side. Most people improve at least partly over 6 to 12 months. This condition is often marked by symptoms including:

• Serious pain in the buttock, hip or thigh.
• Weak and shrinking thigh muscles.
• Trouble rising from a sitting position.
• Chest or stomach pain.
• Weight loss.

Mononeuropathy involves damage to a single, specific nerve. The nerve may be in the face, torso, arm or leg. Sometimes, single nerves in different parts of the body may be affected at the same time. Mononeuropathy often comes on suddenly. Another name for it is focal neuropathy.

Mononeuropathy can cause serious pain, but it usually doesn't cause long-term health issues. Sometimes, the symptoms get better and go away on their own over a few weeks or months. The exact symptoms a person has depend on which nerve is involved. The symptoms could include:

• Double vision, trouble focusing the eyes or an ache behind one eye.
• Not being able to move one side of the face.
• Pain in the shin or foot.
• A feeling of pins and needles.
• Pain or burning feeling in the front of the thigh.
• Loss of feeling in the affected area.

Sometimes mononeuropathy happens when tissue around a nerve puts too much pressure on the nerve. This is called compression. Carpal tunnel syndrome is a common type of compression focal neuropathy in people with diabetes.

Symptoms of carpal tunnel syndrome include:

• Numbness or tingling in the fingers or hands, especially in the thumb, index finger, middle finger and ring finger.
• Loss of strength with a sense of weakness in the hand that may cause you to drop things.

Focal neuropathy that doesn't involve a compressed nerve is less common and usually affects older people.

Talk with your healthcare professional if you notice any of the symptoms above. The sooner treatment starts, the better the chance of preventing other health issues.