What causes sudden tiredness?

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Imagine that you are moving around and completing daily tasks when suddenly you feel tired. Perhaps you're sitting at your work desk or helping your child with his homework when you instantly begin to feel as though you're depleted of energy. Tiredness is described as a feeling of fatigue, exhaustion and an extreme lack of energy. Although sudden tiredness is not a medical condition, it is a warning sign of an underlying health issue.

Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is a condition of prolonged tiredness that is not relieved even after resting. This condition does not have a direct cause, and is experienced mostly by women between the ages of 30 and 50. CFS can affect you without warning; as the condition progresses, you will feel weary and tired as never before. The symptoms can last for months at a time and prohibit you from completing daily activities. Other side effects are forgetfulness, difficulty concentrating, feeling unrefreshed after sleeping and varying headaches.


Stress is a normal, physical response to a perceived danger or threat. Stress can also be the cause of sudden tiredness. Examples of perceived dangers or threats are generally everyday circumstances that can appear to be "piling up" all around you; a situation at work where you fear that you will lose your job, the threat of a utility being disconnected or the danger of losing a loved one due to divorce or illness. Recognisable symptoms of stress are rapid heartbeats, a change in appetite, irritability and inability to sleep. Without proper stress management, these symptoms will become worse.

Kidney Disease

Kidneys have the primary function of removing bodily waste and excess fluid. When the kidneys begin to function poorly, not only could it be the result of other health conditions such as high blood pressure or diabetes, it can lead to kidney disease. Most people who develop kidney disease are unaware of warning signs, which are random bouts of tiredness, swelling of the hands and feet, frequent nocturnal urination and puffiness around the eyes.

Thyroid Problems

The thyroid gland regulates how your body uses energy. When this gland experiences problems functioning, you can develop hypothyroidism or hyperthyroidism. Hypothyroidism is a low thyroid level. In addition to weight gain, you will feel noticeably tired without warning, depression, experience frequent constipation and memory problems. Hyperthyroidism is a high thyroid level. Hyperthyroidism causes sudden tiredness, weight loss, muscle weakness and irritability.

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