Hi, I'm a 21 year old female that has been experiencing sudden tachycardia after a bout of diarrhea. For that last two days I've just been out of whack. I've had recent bout with diarrhea, after, I noticed my lips were dry and pilling, plus a bit of nausea . All of those symptoms have ceased, but what has concerned me the most is this persistent rapid weak pulse which has gotten up to 100 bpm even when I'm resting. My resting heart rate is usually 48 bpm. I'm really concerned, is this mild dehydration or do I need to go to the emergency room. I feel fine though, I have no fever, no headache, nothing, I feel great.