Taking fish oil daily is a good way to help prevent heart disease, heart attacks, strokes, dementia etc.
But if you take too much fish oil you could have side effects including diarrhea, nosebleeds, rashes, loose stools, heartburn, bad breath and belching.
If you experience any of those side effects then you're likely just taking too much fish oil and should decrease your intake of fish oil or you might be allergic to fish oil.