Bad Breath is caused by bacteria building up in the mouth. Commonly caused by a lack of oral hygiene. These bacteria can cause tooth and gum disease if left untreated. There is also evidence that shows that tooth and gum disease can lead to heart valve disease as the bacteria can move from the mouth area to the heart.
death...
DEATH.
Weight gain and health problems
Nuclear Test Site in Semipalatinsk caused major environmental and health problems.
Crack is bad because it can cause health problems, addition, and other problems.
Polonium can be a cancer cause.
it causes health problems, and is really bad for your skin
probably mal nutrition
like cancer,asthma(problems in breathing) etc.
Scurvy and rickets are some health problems caused by lack of nutrition, but I don't know many more.
one of the things that caused some of the economic problems would be they had a bad economy and it caused there empire to be overthrown
Obesity is a bad thing because it can cause many health problems.