Let's face it -- just about everyone has faked being sick at least once to avoid going to work. Using a gravelly voice and sounding tired may be enough to get by, but Metro has some tips to really sell it to your boss.
Flu -- Know the symptoms vs. a cold, and take more than a day off, because the flu takes longer to get over.
Food poisoning/Gastroenteritis -- Don't get fancy and say you have gastroenteritis, just stick with food poisoning.
Migraine -- This is a better excuse than just a headache, because the answer to that might be to just take a couple of Advil and go in to work. Women are more likely to suffer from migraines, so this is a good excuse for them.
Back/neck pain -- You might want to mention taking anti-inflammatory drugs and using hot and cold packs.
Whiplash -- Be ready to wear a collar for a little bit if you really want to be convincing with this one.
Sprained ankle -- Have a good excuse for how it happened and practice your limp for when you return to work.
Conjunctivitis (Pink Eye) -- Be sure to mention how contagious this can be. Your boss will want you to stay home.