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:
English. Hyphens are used in some compound words as a way to make the word easier to read as well as help clarify words that are used together. For examples to-do, merry-go-round, high-risk, T-shirt, and sixty-six are all words with hyphens.