1 Angina Pectoris: It is described as a pain located at the back of the breast bone which may be sharp or dull. This sensation may radiate or crawl to the hand, arm, left shoulder, or jaw.  Vasculitis: When the small to medium sized arteries are inflamed, head tingling and numbness may result.
Most species of shark eat things like fish, crustaceans, mollusks, plankton, krill, marine mammals and other sharks. Sharks also have a very acute sense of smell that allows them to detect blood in the water from miles away.
Shark bites occur more frequently in murky water. They are attracted by lights, noise, or splashing, and smell. For theses reasons surface swimming should be kept to a minimum, in shark waters. Research shows that bright colors attract sharks more than dark objects, so it is better for divers to wear dark colors. Blood in the water can attract sharks from long distances. They can sense blood in the water in concentrations as little as 4 parts per million.