What Are the Causes of a Lack of Energy?

Fatigue is the collective term used to describe a feeling of low energy, sleepiness and lack of motivation. Occasional fatigue is common, and can usually be attributed to notable lifestyle factors, such as lack of sleep or working too hard. In some cases, however, fatigue is persistent and of unknown origin, which may indicate the existence of an underlying condition, such as heart disease, that requires medical attention.

Poor Nutrition

• Poor eating habits and unhealthy food choices can cause nutritional deficiencies that impair the body's ability to generate energy. Energy production in the body is dependent on B-complex vitamins, especially B12 and B5, vitamin C, magnesium and CoQ10. Excessive consumption of soft drinks, chocolate or caffeine is known to cause a depletion of magnesium in the body, which can result in a lack of energy, according to Dr. James Balch, author of "Prescription for Nutritional Healing."

Lifestyle Factors

• A lack of energy may be caused by obvious reasons, such as not getting sufficient amounts of sleep, overwork or unhealthy habits, such as caffeine or drug use, over-exertion or dehydration from lack of fluid intake. Ironically, long periods of physical inactivity or not getting enough exercise can also cause a lack of energy. A daily walk outdoors or another form of routine exercise may help improve energy levels.

Medical Conditions

• A chronic lack of energy accompanied by extreme hunger, increased thirst and urination, blurred vision, frequent infections, weight loss or sores that don't heal may indicate diabetes. Fatigue can also be a sign of anemia, a condition in which there are not enough healthy red blood cells to carry adequate oxygen to the body's tissues. Fatigue and sluggishness accompanied by constipation, increased sensitivity to cold, dry skin, puffy face, hoarseness, elevated cholesterol, weight gain, muscle aches, joint stiffness, depression and brittle fingernails may indicate a thyroid disorder.

Emotional Factors

• Fatigue that is accompanied by other symptoms, such as irritability, unhappiness and lack of motivation, may be caused by depression, grief or chronic stress. Spending more time outdoors, starting an exercise routine or finding new interests or hobbies may be effective at improving one's energy level.

Considerations

• Other possible factors that can contribute to a lack of energy include chronic low-grade infection, allergies and heavy metal toxicity. Several over-the-counter and prescription drugs can also contribute to fatigue, such as antihistamines, cold remedies, pain medications, heart medications and antidepressants.