Dear Doctor, For about 3 months now, I feel weak even when I have eaten food. What could this be? Dan Dear Dan, Weakness is entirely very subjective. One can feel weak for many reasons. Mental stress, lack of adequate sleep and anxiety can cause weakness in spite of eating well. Chronic constipation tends to create dullness and feeling of weakness. Among disease conditions, uncontrolled diabetes is the most common cause for a person to lose weight and feel weak, in spite of even increased appetite. This happens because the body fails to use the available glucose. One tends to feel weak with thyroid disorders as well. Chronic anemia, i.e. deficiency of adequate red blood cells in the body also tends to produce weakness, even if a person has been eating adequately. Chronic alcoholism, cigarette smoking and other addictions tend to deprive body of essential nutrients making an individual feel weak. A person can feel weak transiently due to acute medical problems like flu, acute diarrhoea and / or vomiting, fever, etc. Intestinal worms can cause weakness, but there would be other associated features like abdominal pain, nausea and / or vomiting. Chronic infections like tuberculosis, cancer, cause weight loss and weakness. In such chronic conditions there would be other predominant symptoms of underlying diseases like fever, night sweats, loss of appetite and cough. Some drugs like anxiolytics, anti depressants, anti allergy, cause somnolence and weakness. A person should take a balanced diet to keep the body strong. This should include fresh vegetables, fruits, whole grains, cereals, milk and healthy meat products. Good food hygiene helps to keep away food borne infections like worms and protozoa. Regular physical exercise is very useful in maintaining a strong body. Abusive substances like alcohol, tobacco, should be avoided. Simple blood tests can reveal any weakness causing condition like diabetes or a thyroid disorder. If any result comes positive, all these conditions are very well curable. Dr Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital