That is jet lag. It is due to the maladjustment of the biological clock. Like our wrist watch body maintains a clock for its activity, the circadian rhythm, called biological clock. It is a function of the brain.

Acid can erode enamel of tooth and immediate brushing of tooth causes more harm.

In Indian mythology, there was a story related to the worship of Sun God. Samba, son of Lord Krishna was cursed to suffer from leprosy due to some evil act of his. He realized the mistake and sought the remedy. It was suggested to him that, only Sun God had the power to heal that disease, and he should make the god happy by prayers to get his blessings. He followed that and got cured. Whatever might be the behind story, it goes without saying that sun rays have much more implications in our lives, than originally thought of.

Hydatid disease is caused by Echinococcus Granulosus. These larva remain in the muscle tissue of animals. The undercooked or uncooked flesh if taken, may cause the disease.