When the muscles are weak and a person is unable to do the daily tasks of life, it causes weakness. There is tiredness, drowsiness and lethargy. The affected person has to exert hard for doing daily activities. There is feeling of sluggishness. The person loses interest in performing tasks due to lack of energy. There are sleep and concentration problems. The main causes of weakness are poor immunity, missing food, stress, physical strain, poor nutrition and lack of sleep. Some diseases like anemia, cancer and diabetes can also cause weakness. The best option to treat this problem is using home remedies. Following are top 21 home remedies for curing weakness.