One of the most frequent complaints people have when they go to their physician is fatigue. We all have suffered through days or weeks of this and are delighted when it finally passes. But many people suffer through weeks, months and years of this disabling symptom and are often frustrated by the lack of answers.

Early diabetes and hypothyroidism are both disorders of your endocrine system that are very frequently associated with fatigue. Usually these conditions are screened for at most general physicals (if you get them) but can be missed if not specifically looked for.

But I would like to review some of the more common but not always obvious causes of fatigue.

The easiest problem to screen for is a sleep disturbance.

Now just because someone falls asleep when their head hits the pillow does not mean they do not have a sleep disturbance. The most common sleep disturbance is snoring/sleep apnea. “But I don't snore!” Really? Who says. Your spouse snores too so their no help. A good look in your mouth might give you a clue if you snore. If your uvula (that thing that hangs down the back of your throat) ends below your tongue when you go “aaah” (do this in the mirror when no ones looking) and/or you have a soft palate that extends downward—you probably are a snorer (at least some of the time.) If this is the case then you might want to ask for a sleep study. Former sleep apnea patients often report that before treatment they felt like they had cotton in their brains and after treatment they feel much more alert and energetic. But any sleep pattern that does not give you at least 7 hours of uninterrupted sleep will cause chronic fatigue.

Several nutritional deficiencies are related to fatigue. The most common are deficiencies in iron, Vitamin B12, and Vitamin D.

Women can obviously become iron deficient due to their menses, but both men and women can develop iron deficiency due to some type of chronic slow blood loss from he intestine. The most serious would be a colonic bleeding polyp or colon cancer. Other causes of blood loss are severe esophageal reflux, gastric ulcers/gastritis, and AVMs (tangle of blood vessels that are too close to the surface of the intestines.)

Vitamin B12 is a classic cause for fatigue and can present as pernicious anemia—an anemia caused by an autoimmune condition which prevents the absorption of Vitamin B12 in the lower intestine. But people without pernicious anemia can also develop significant, symptomatic B12 deficiency. The absorption of B12 is odd. First the stomach produces a protein that binds to the B12 molecule then this complex travels to the lower intestine where it is absorbed. Recently it was discovered that an acid stomach is required to bind the B12 in the stomach. So chronic antacid users (ie prilosec, zantac, prevacid) can slowly develop B12 deficiency. Often, by taking mega-doses of Vitamin B12 (1000mcg daily) you can force the vitamin into the tissue. Vitamin B12 is needed for your nervous system and your bone marrow. Patients with low B12 are often extremely pale, frequently more so than you would expect from the degree of their anemia.

Vitamin D is a recently popular vitamin that everyone is being tested for. Normal levels are 35-50 and patients with levels below 10 are not uncommon. Some people are lactose intolerant so avoid all dairy. Or they avoid dairy to reduce the fat calories. Sun light is needed to active the Vitamin D we ingest from our diet so us fools in the Northeast can get very low. You really cannot get toxic from B12 but too much Vitamin D can cause kidney stones so best be careful before taking to much Vitamin D.

Lack of exercise is another counter intuitive cause for fatigue. Tell a person who is always tired they need to exercise more and your liable to get quick smack across the head. But this type of fatigue just can't be rested away. The more you rest, the worse it gets. Even modest exercise can help lift this fatigue. Walking, swimming or biking for 20 minutes 3-5 times a week can often be enough to slowly lift the energy level to let you know you are on the right track.

Hopefully this will be helpful for you and look for more blogs in the near future addressing other problems in primary care.