Lethargy can feel like ordinary fatigue, and is not always accompanied by clear signs of illness. Short-term lethargy can be caused by physical fatigue, stress, or lack of sleep. Lethargic body can also be a symptom of a more serious medical condition. If the experienced lethargy is persistent or severe, it is important to consult a doctor to determine the underlying cause.

Weakness and fatigue are not always caused by physical factors. Psychological conditions can also play an important role. Some psychological conditions that can cause the body to feel weak include: Stress: Stress hormones such as cortisol can disrupt sleep patterns, appetite, and other bodily functions, worsening the feeling of weakness. Emotional Shock: Traumatic events or intense emotional situations, such as deep sadness, can cause physical and mental fatigue.

Some medical conditions can also cause asthenia. Conditions that usually last briefly can cause weakness and fatigue. Examples include:Infections: Viral or bacterial infections, such as the flu, can cause fatigue, body aches, and fever that contribute to a feeling of weakness.Poisoning: Exposure to harmful substances, such as carbon monoxide, can cause weakness, dizziness, and nausea.

Anemia and Blood Disorders: Anemia occurs when the body lacks healthy red blood cells to carry oxygen. Weight Deficiency or Excess: The body requires energy to maintain a healthy weight, and a deficiency or excess of energy can cause fatigue. Malnutrition or Nutritional Imbalance: Deficiency of vitamins or minerals such as iron, vitamin B12, or vitamin D can cause fatigue.

Some behavioral factors and lifestyles that can contribute to a feeling of weakness and fatigue include: Smoking: Smoking can damage the lungs and reduce oxygen flow to the entire body, causing fatigue and shortness of breath. Lack of Exercise or Excessive Exercise: Lack of exercise can make the body weak, while excessive exercise can cause fatigue and muscle weakness.