Why do I have a fever?

Background: 19. 150 pounds. 5'8''. High triglycerides and cholesterol. Don't do drugs. Don't smoke. Not on any medication. Anything else you want to ask but I don't have here, I'll add to 'Additional Details'

The past few days, in the middle of the day, I've found myself suddenly getting tired and almost unable to move because of the strong fatigue. I checked my blood sugar, it was 105 - normal.

The past two days my temperature has been 99.0. However today when I've checked, it's gone from 99.3 to 99.6 within just a few hours.

Right now, I'm fine. But I have severe fatigue spells and don't know what could be causing this. I'm also having problems with short-term memory and other things, but these two things - fatigue and low-grade temperature - stick out the most.

Any ideas...?

Don't want to sound smart alec, but you're probably just sick. Cold/flu/bugs .... Sounds like a normal illness to me. Go to the doctor and get a check up. Holding a fever for several days is not good for you.

any cough shortness of breath diarrhea? painful urination? fever is a body's way of trying to get rid of harmful bacteria go to doctor and have checked