Every day of the week, a CNNHealth expert doctor answers a viewer question. Wednesday is Dr Otis Brawley, chief physician at the American Cancer Society.

Asked by Mike from Tennessee

Can diabetes be a (possible) cause of fatigue, leg pain and lower back pain? I had energy surges for 10 to 15 minutes, but then I need to sit down for about 10 minutes and I’m ready to go full steam ahead. PLEASE, thank you, Mike

Expert response

Dear Mike:

Thank you for this important question, as many people with diabetes complain about these symptoms. The answer is that diabetes itself is probably not the cause of your fatigue, lower back pain, and leg pain. Things that cause type 2 diabetes (also called adult diabetes), such as a problem with your weight and lack of exercise, are usually the cause of these symptoms.

Fatigue has three components: 1. The inability to initiate an activity. 2. Reduced ability to maintain an activity. 3. Difficulty concentrating and remembering.

Fatigue should be distinguished from drowsiness, shortness of breath on exertion, and muscle weakness, although these can also be associated with fatigue. Fatigue that lasts six months or more is called chronic fatigue. Chronic fatigue is not necessarily the entity known as chronic fatigue syndrome, which is a diagnosis after excluding all other causes.

Fatigue in everyone should be evaluated by a healthcare professional to rule out all possible causes and to get advice on how to treat it. Other medical causes of fatigue are side effects of medications, thyroid dysfunction, high calcium levels, rheumatologic disease, adrenal, kidney or liver problems.

Some infections such as tuberculosis or hepatitis can cause fatigue, and indeed fatigue may be their only symptom. Depression is also a major cause of fatigue.

Although uncommon, uncontrolled diabetes can be the cause of fatigue. These patients usually also have other symptoms of diabetes such as excessive thirst, frequent urination, and blurred vision. Some medicines used to treat diabetes can cause fatigue by causing anemia or a metabolic change known as lactic acidosis. These are unusual side effects.

Many patients use the word fatigue to complain of drowsiness. A large proportion of adults and especially a large proportion of those who are obese have obstructive sleep apnea. This is a condition in which the sleeping person literally stops breathing for a few seconds, several times a night. Each time, they wake up to start breathing again.

People with obstructive sleep apnea usually don’t realize that they’ve disturbed their sleep several times during the night. This leads to drowsiness throughout the day because the person literally hasn’t had a good night’s sleep. Sleep apnea is usually treated with a continuous positive airway pressure device, commonly known as a CPAP, which increases the pressure of the air you breathe during the night.

If a root cause of fatigue cannot be found, it can often be treated with cognitive behavioral therapy or graduated exercise therapy. An activity and exercise regimen is often successful.

Although your complaints may not look like this, many diabetics with foot and lower leg pain suffer from it due to nerve damage caused by diabetes. This is called diabetic neuropathy. Diabetic neuropathy can also present with numbness in the feet and lower leg. Diabetic neuropathy is very common and can be treated.

Nonspecific pain in the lower back and legs is most often due to muscle weakness. Strengthening the abdominal and lower back muscles can often provide incredible relief from many lower back pains. Pains that descend from the back into the legs are possible signs of nerve irritation and even conflict in the spine. This too can often be treated with appropriate exercises supervised by a physiotherapist.

As you can see, it can be very complicated and involve several different issues. An intern or family doctor can usually begin the assessment and determine if a specialist needs to be seen.