Diabetic Neuropathy – Symptoms and Causes

Overview

Diabetes-related nerve damage affects many people with the disease. About half of all diabetics may develop this condition.

It often hits the legs and feet but can harm other body parts too.

This nerve problem can cause different symptoms. Pain and numbness in the legs, feet, and hands are common. Some people also have trouble with digestion, urination, and heart function.

The symptoms vary widely. Some people barely notice them. Others feel severe pain that affects their daily life.

The good news is that careful blood sugar control and healthy habits can help prevent nerve damage or slow it down. Regular check-ups with healthcare providers can catch problems early.

Signs You May Have Diabetic Nerve Damage

Nerve Pain in Hands and Feet

Nerve damage in the feet and legs (and later hands and arms) is the most common type of diabetic nerve problem.

You might notice these symptoms, which often feel worse at night:

• Numbness or trouble feeling pain or temperature
• Burning or tingling feelings
• Sharp pains or muscle cramps
• Weak muscles
• Very sensitive skin—even light touch can hurt
• Foot problems like sores, infections, or bone damage

Some people describe the pain as “pins and needles” or like an electric shock.

Often the symptoms start gradually and may affect both sides of the body.

Problems with Body Functions

Diabetes can damage nerves that control automatic body functions. This might cause:

• Not noticing when blood sugar drops too low
• Feeling dizzy or faint when standing up
• Bladder or bowel issues, like trouble emptying completely
• Stomach problems including nausea, vomiting, feeling full quickly
• Trouble swallowing food or liquids
• Vision adjustment difficulties
• Sweating too much or too little
• Sexual problems like vaginal dryness or erectile issues

These symptoms can greatly affect daily life and comfort. They happen because the nerves that control your internal organs are not working properly.

Hip and Thigh Nerve Damage

This type of nerve problem often affects the nerves in your lower body. It typically starts on one side but might spread to both. Signs include:

• Strong pain in the buttock, hip, or thigh
• Thigh muscles that become weak and smaller
• Trouble standing up from a chair
• Pain in the chest or stomach area

This form can cause significant disability but often improves with time and treatment.

Single Nerve Problems

Sometimes diabetes damages just one nerve. This can happen anywhere in your body and may cause:

• Vision problems like double vision or trouble focusing
• Face drooping on one side
• Numb or tingling hands or fingers
• Hand weakness that makes you drop things
• Pain in the shin or foot
• Foot drop (trouble lifting the front of your foot)
• Pain in the front of your thigh

These problems may come on suddenly and can be quite painful, but they usually improve or resolve with time.

When to See a Doctor

Contact your healthcare provider if you notice:

• Foot problems like infected cuts or sores that don’t heal
• Nerve symptoms such as burning, tingling, weakness, or pain in hands or feet that affect daily life or sleep
• Changes in bodily functions related to digestion, urination, or sexual activity
• Balance issues including dizziness and fainting

People with diabetes should begin screening for nerve damage right after being diagnosed with type 2 diabetes or five years after a type 1 diabetes diagnosis.

After initial screening, yearly checkups are recommended to monitor for nerve problems.

Causes

The root cause of different neuropathy types remains unclear. Research suggests that persistent high blood sugar damages nerves over time, disrupting their signal transmission ability.

This elevated glucose also harms the walls of capillaries (tiny blood vessels) that deliver oxygen and nutrients to nerves. When these small vessels weaken, nerves receive inadequate nourishment, contributing to diabetic neuropathy development.

Risk Factors

Several factors increase the chance of developing diabetic neuropathy:

• Blood sugar management – People who don’t keep their blood sugar under control face a higher risk of nerve damage.
• Time with diabetes – The longer someone has diabetes, especially with poor blood sugar control, the more likely they are to develop neuropathy.
• Kidney problems – Diabetes can harm kidneys, which then allows harmful substances to build up in the blood and damage nerves.
• Excess weight – Having a BMI of 25 or higher may increase nerve damage.
• Tobacco use – Smoking damages blood vessels, reducing blood flow to the feet and legs, which can harm nerves and slow healing.

These factors often work together. For example, someone who has had diabetes for many years, smokes, and struggles with blood sugar control faces much higher risks than someone with just one risk factor.

Health Complications of Diabetic Neuropathy

Diabetic neuropathy can lead to several serious health problems that affect daily life. These complications can range from mild inconveniences to life-threatening conditions.

Warning Signal Failure
When nerve damage affects the autonomic system, people may lose their ability to detect low blood sugar. Normally, blood sugar below 70 mg/dL causes shaking, sweating, and rapid heartbeat. Without these warning signs, dangerous hypoglycemia can occur without notice.

Foot and Limb Problems
Nerve damage often causes numbness in the feet, making it hard to feel injuries. Small cuts can develop into serious wounds without proper care. In severe cases, infections may reach bone or cause tissue death, sometimes requiring:

• Toe amputation
• Foot removal
• Partial leg amputation

Urinary System Issues
Nerves controlling the bladder can be damaged, preventing complete emptying during urination. This creates two main problems:

1. Bacteria buildup causing frequent infections
2. Inability to control urination, leading to leakage

Blood Pressure Irregularities
Damage to nerves that regulate blood flow can cause sudden drops in blood pressure when changing positions. Standing up may trigger dizziness or fainting.

Digestive Challenges
Nerve damage in the digestive system often leads to constipation, diarrhea, or both. Some people develop gastroparesis, where the stomach empties too slowly or not at all, causing bloating and indigestion.

Sexual Problems
Autonomic nerve damage frequently affects sexual function. Men may experience difficulty achieving or maintaining erections. Women might have problems with natural lubrication and arousal.

Sweat Gland Dysfunction
Neuropathy can disrupt normal sweating patterns. Some areas may sweat too much while others too little. This makes body temperature regulation difficult and can cause discomfort in various environments.

Ways to Prevent Diabetic Nerve Damage

Managing Blood Sugar Levels

Keeping your blood sugar under control is key to preventing nerve damage from diabetes.

The American Diabetes Association suggests getting your A1C test at least twice yearly. This test shows your average blood sugar over the past 2-3 months.

While A1C goals should be personalized, many adults aim for less than 7.0%.

If your levels are higher than your target, you might need to adjust your:

• Daily medications
• Diet choices
• Physical activity routine

Taking Care of Your Feet

Foot problems like non-healing sores, ulcers, and even amputation can happen with diabetic nerve damage.

Daily foot care routine:

1. Inspect your feet daily – Look for blisters, cuts, redness, swelling, and peeling skin. Use a mirror or ask someone to help check areas you can’t see easily.

2. Keep feet clean and dry – Wash with lukewarm water and mild soap daily.
   Avoid soaking your feet and dry them thoroughly, especially between your toes.

3. Apply moisturizer – This prevents cracking, but avoid putting lotion between your toes where it might cause fungal growth.

4. Trim nails properly – Cut straight across and file edges smooth. If this is difficult, a podiatrist can help.

5. Wear appropriate socks – Choose clean, dry socks made of cotton or moisture-wicking materials without tight bands or thick seams.

6. Choose proper footwear – Wear cushioned, well-fitting closed-toe shoes that allow toe movement. A foot specialist can help find properly fitted shoes to prevent problems like corns and calluses.