The Four Types of Diabetic Neuropathy
Most of us associate peripheral neuropathy with diabetes. What might be a surprise is that there are three other forms of neuropathy that are also common to diabetics.
Diabetic neuropathy is the result of prolonged periods of excess glucose in the blood damaging fragile nerve fibers. Hyperglycemia also damages the walls of the many blood vessels in the body, including the capillaries that provide the blood supply that supports the nervous system. Finally, high glucose levels interfere with the ability of the nerves to send signals.
Taken together, this triad of damage causes first numbness, then extreme pain, in the nerves in various areas of the body.
This is the most common form of neuropathy to afflict diabetics. Symptoms usually begin in the feet and legs, then move to the hands and arms. Symptoms include:
- Loss of pain or temperature sensation
- Tingling or burning
- Acute sensitivity to touch
- Sharp pains or cramps
- Bone and joint pain
- Muscle weakness
- Loss of reflexes, beginning with the ankle
- Loss of balance and coordination
- Acute injury to the foot, including ulcerations, infections, deformities
The autonomic nerves are the ones that control the beating of the heart, breathing, bladder control, movement of stomach contents, movement of waste through the intestines and sexual response.
These are the nerves that act without being directed by conscious thought. Symptoms include:
- Hypoglycemic unawareness (an inability to sense that blood glucose has dropped too low)
- Bladder issues (infections, retention or incontinence)
- Constipation or uncontrollable diarrhea, or both
- Gastroparesis (slowed emptying of the stomach)
- Difficulty swallowing
- Erectile dysfunction
- Sexual difficulties in women
- Increased or decreased sweating
- Problems regulating body temperature
- Changes in way eyes adjust when changing from light to dark
- Increased heart rate when at rest
- Loss of the body’s ability to adjust blood pressure and heart rate
Radiculoplexus neuropathy, also known as diabetic amyotrophy, femoral neuropathy or proximal neuropathy, affects nerves in the thighs, hips, buttocks or legs. Symptoms are felt usually, but not always, on one side of the body, and may improve with time. Symptoms include:
- Acute pain in the hip and thigh or buttock
- Atrophied muscles with associated weakness and disability
- Abdominal swelling, if nerves there are involved
- Weight loss
This type of neuropathy (also called focal neuropathy) causes damage to only a single nerve, which may be located anywhere on the face, torso or leg. It comes on suddenly and is usually experienced by older adults.
While painful, the pain is temporary, usually lasting no more than a few weeks or months. Once it resolves, there is no lingering damage.
Symptoms are specific to the affected nerve, and may include:
- Paralysis on one side of the face (Bell’s Palsy)
- Difficulty focusing, double vision or pain behind one eye
- Pain in the shin or foot
- Pain in the lower back or pelvis
- Pain in the front of the thigh
- Pain in the chest or abdomen
As many as 70% of diabetics have some degree of neuropathy, even if they are asymptomatic. The longer since the diabetes diagnosis, the more likely the patient will have neuropathy.
Other risk factors include smoking, obesity, elevated blood lipids and high blood pressure.
Diabetics should regularly examine the bottom of the feet, and the hands and fingers, looking for damage. Neuropathy leads to slow to no healing at these sites, and the result of a minor injury could wind up being amputation if the injury is ignored.