The peripheral nervous system is the term for all the nerves outside the brain and spinal cord. (The nerves within the brain and spinal cord are called the central nervous system, or CNS). The peripheral nerves carry information back and forth between the CNS and the rest of the body.
Peripheral neuropathy (PN) is caused by damage to the peripheral nerves. It's a common side effect of many chemotherapy medicines. You might hear this called chemotherapy-induced peripheral neuropathy, or CIPN.
PN can cause pain, numbness, tingling, burning, and other problems around the body. Sometimes it lasts for only a short time after cancer treatment. It can get better as nerves heal over time. But for some people, it can last months or even years. It depends on how much chemotherapy you had and the type you had. It can also depend on where the tumor was and the type of radiation or surgery that was done. Other health conditions, such as diabetes or thyroid problems, have been linked to PN, too.
Sometimes tumors press on or grow into and damage nerves. Surgery and radiation therapy can also cause nerve damage that leads to PN. But the most common cause is chemotherapy. Certain kinds of chemo can damage nerves. This often starts during treatment. PN may get worse as treatment goes on.
Symptoms depend on which nerves are damaged. The most common symptoms include:
Prickly pain ("pins and needles")
Sharp, stabbing pain
Symptoms often start in your fingers and toes and then move into your hands and feet. Over time, they may move up into your ankles, legs, and arms. The symptoms may feel worse when you touch something, or wear gloves or shoes.
Other symptoms may include:
More sensitivity to cold, heat, and touch
Trouble sensing heat and cold
Trouble using your fingers, such as problems texting, picking up small items, or buttoning a shirt
Limbs that feel heavy or weak
Muscle cramps in your hands, feet, or both
Tripping, stumbling, or balance problems
Numbness that makes it hard to tell if you are hurt
If not treated, over time PN can lead to:
Changes in how you sweat
Bowel problems like diarrhea or constipation
Peripheral neuropathy can't be prevented, but it can be managed. It's best to tell your care team about it right away so treatment can be adjusted.
Nerves heal slowly, and PN may get better over time after treatment ends. But sometimes it gets worse.
PN can't be cured, but treatment can help. Treatment may include medicines that can lessen nerve pain, such as:
Numbing medicine in a patch or cream to put on your skin
The antidepressant medicine called duloxetine
Opioids, like codeine or morphine, for severe pain
Other kinds of treatment include:
Transcutaneous electric nerve stimulation (TENS). This therapy uses mild electric currents to help relieve some kinds of pain. You can buy a TENS unit at a pharmacy, but talk with your healthcare provider first.
Acupuncture. This type of therapy uses very thin needles that are put in certain areas of the skin. The needles are left in for up to 30 minutes and then removed. This can help relieve pain all over the body. Check with your healthcare provider to be sure it's safe for you to do this treatment and to find a trained acupuncture therapist.
Hypnotherapy. A trained therapist can teach you how to reach a state of relaxation that helps relieve pain. Your provider can help you find a skilled, trained therapist.
Guided imagery. This type of therapy helps you create images in your mind to help lessen feelings of pain. You can do it at home or work. Many books and websites have instructions for how to do guided imagery.
Physical therapy. For this treatment, you work with a trained therapist to make parts of your body stronger and improve your balance. You can learn how to exercise safely, which can help reduce pain.
Occupational therapy. This type of therapy focuses on how to help you do activities of daily living. These include bathing, dressing, cooking, and other tasks.
There are some things you can do to help manage the symptoms caused by PN. For instance:
Don't drink or limit alcohol. It can worsen nerve damage.
Watch your blood sugar. If you have diabetes, make sure your blood sugar is under control. High blood sugar can make nerve damage worse.
Stay out of hot or cold temperatures. Take lukewarm baths and showers. Dress for the weather to help keep heat or cold from making your symptoms worse. Wear gloves in cold weather.
Eat well. Try to eat low-fat meats and dairy products. Focus on vegetables, fruits, and whole grains.
Nerve damage means you are less likely to feel injury, and you may take longer to recover from it. You'll need to take extra steps to protect yourself from injury. For instance:
Check your feet daily. Don't walk around barefoot. Make sure to wear shoes that fit well. Check for blisters, cuts, or other problems every day.
Make sure your home is safe. Put nonskid pads under rugs. Lower the setting on your hot water heater to help prevent burns.
Prevent falls. Use a walker or cane if needed for balance. Put hand rails and nonslip mats in the tub or shower.
Protect your hands. Wear gloves when you clean, garden, or cook. Be extra careful when using knives and scissors.
Make sure you are safe to drive. Check that you can fully feel the pedals and steering wheel. Make sure you can apply enough pressure on the brakes and can make quick movements when steering if needed.
Make sure to talk with your healthcare providers if you need help. Tell them if symptoms get worse or if you have new symptoms. Also let them know if you're having trouble with daily tasks. They can help you find ways to manage PN so you can do the things you need and want to do.