If you are fatigued and tired, chronically, consistently, every day, you might have some issues to deal with beyond merely getting some more sleep. Here are the main sources of fatigue; some have quick fixes, and some are incurable:

People with sleep apnea believe they are getting enough sleep when they are actually waking up throughout the night, briefly, having trouble breathing. Your doctor will only be able to diagnose this after a sleep study, but CPAP devices that help keep your airway passages open while you sleep are a ready solution.

If you do not eat enough, expect to be fatigued. Always eat breakfast and be certain that protein and complex carbohydrates are a part of every meal. Similarly, an iron deficiency – anemia – can likewise generate chronic fatigue. In this case, be sure to include moreiron-rich foods, such as lean meat, liver, shellfish, beans, and enriched cereal, in your diet.

You can eat the wrong things, too, and get slammed by fatigue. Too much caffeine, perhaps counter-intuitively, can cause fatigue amidst all the elevated blood pressure and jitter.

And don't forget to drink! Not drinking enough liquids can make you just as tired as not eating enough food. Drink water throughout the day; you'll know you're getting enough when your urine is consistently clear.

Diabetics suffer from extraordinarily high levels of sugar in their bloodstream that aren't being converted to energy inside their cells.  Consistently being tired even though you think you are eating and sleeping enough may be a tip to see your doctor about checking you for diabetes, or fibromyalgia – another disease for which fatigue is a symptom.

Allergies and intolerances to certain foods can manifest themselves as fatigue after you eat them. This is one you can self-diagnose if you keep a food diary, or just see your doctor about running a food allergy test.

If you find your are fatiguing easily after doing certain chores or jobs around the house that never used to tire you out, it could be a sign of heart trouble. See your doctor as soon as you make that connection.

Finally, there is the disease for which fatigue is the raison d'être: chronic fatigue syndrome, sometimes abbreviated as CFS. There is no clean cure or quick fix for this, but your doctor can provide you with advice on improving your sleeping habits and exercise program to provide some relief.