Why is being underweight a hazard to health?

Does the flu virus affect the nervous system? What filters blood inside of a kidney? What is propionibacterium acnes? What is the Cause of lack of potassium in the body? Has anyone who did not get the flu shot died from the flu? Can your mestral cycle last for two days? What are the two categories of nerves belonging to the peripheral nervous system? Why are women more likely to contract urinary tract infections? Do any duggar child have down syndrome? Which part of the digestive system do the laxatives act on? 3 types of written communication? What were the names of any people involved with the bubonic plague? Are you an enabler if you give an alcoholic money? Why use the Thyroid Uptake and scan on the thyroid? What is it called when you wake up for fast? What appears when dermis elasticity declines from age or excessive sun exposure? Why do we need to supply manure? Is cardiac function measured out of a possible100 percent? What does rhinoplasty involve? If you kiss someone who smokes will you get what they will get e.g lung cancer?