Sickness (roga) is the malfunctioning of the organism due to infection or injury. If every sickness were caused by past kamma, as some misinformed Buddhists maintain, then taking medicine would be pointless. But the Buddha listed eight causes of sickness, only one of which is kamma, the others being imbalance of bile, phlegm or wind, the bodily humors, the weather, improper care and accidents (S.IV,230).
In another place he said that a poor diet can also lead to sickness (A.III,144) as can overeating (M.I,473). The Buddha defined health (anàmaya or àrogya) as having well-being, good digestion, not being over-cold or over-hot, balance and being capable of activity (A.III,103). He considered good health to be a true blessing and an important prerequisite for practicing the Dhamma saying; ‘Good health is the highest gain’ (Dhp.204). He advocated a light diet because it contributes to ‘freedom from illness, to health, to strength and to bodily ease’ (M.I,473) and he was aware of the connection between exercise and health (A.III,30). He also asked his disciples to contemplate the blessings of having good health and to use the opportunity to practice the Dhamma (A.III,103). The Buddha considered visiting and nursing the sick to be virtuous acts and out of compassion he did both. He once said, ‘He who would nurse me, let him nurse the sick’ (Vin.IV,301). He also said that an employer has an obligation to look after their employees when they are sick (D.III,191).