Very high triglycerides can be caused by poor diet and not enough exercise. You may also have inherited very high triglycerides from a parent. Your doctor will tell you how to manage your triglycerides. If your weight is higher than what is considered healthy, losing even 5 pounds may help lower your triglycerides.
WORD likes it un-hyphenated but I don't. Long-term should be hyphenated but longtime should not be hyphenated, at least until a few more decades pass and the grammatical rules for the use of hyphens either relax or fade away. Here is part of an erudite commentary on this subject:
There are two commandments about this misunderstood punctuation mark. First, hyphens must never be used interchangeably with dashes (see the Dashes section), which are noticeably longer. Second, there should not be spaces around hyphens. Hyphens' main purpose is to glue words together. They notify the reader that two or more elements in a sentence are linked.