Recently I have come down with the flu, and am experiencing regular flu symptoms. What is troubling though, something that is rather new, is that at random Ill feel my heart give three hard thumps and then Ill get really dizzy. This will happen while walking, standing, or lying down. Could it be that I am dehydrated?
HIT hanks for posting your query to Chat Doctor.  First let me tell about dizziness causes. There are many causes for Dizziness, from simple and easily treatable causes to serious causes. Simple causes are :1. Abnormalities in BP: Both high and low BP can cause dizziness. 2. Abnormalities in Blood sugars: Both high and low Blood sugars can cause dizziness.3. Abnormalities in blood sodium levels. 4. Low Hemoglobin (Anemia)5. Inner Ear problems. Some serious problems are :1. Heart Problems2: Brain problem In your case the problem could be either in Blood pressure or in Heart as thumping sensation in heart (called as Palpitations) is seen in either low/high Blood pressure or in heart problem.  I advise you to get your blood pressure checked in lying down position and Standing position. Also get an ECG done and revert with reports.  Deny Chat Doctor.