Yes - see doctor immediately
No. When you acquire an STD it usually takes at a minimum 3 days for any symptoms to appear (depending on the disease). Probably just sore/red/swollen from relative over-use.
it could be infected go see a dr
A red, hard, swollen scabbed thing on your arm could be a bug bit. If it doesn't heal in a few days, have it checked by your doctor.
it could be an infection you should see a doctor.
There could be any number of reasons why your finger is red and swollen - but it usually indicates some type of inflammation. It happens to me because of arthritis. I suggest you talk to a doctor.
It could have a tumour.... i would contact your vet immediately.
Some kinds of vaginal infections, improper tampon use, or other irritants cause inflammation of the cervix which makes it red.
The arm is probably red and swollen after shooting up because the body is rejecting the drug that was injected. It could also be an allergic reaction to the drug. Another reason could be that an artery was hit. The only way to know for sure is to seek the advice of a physician.
If its been swollen, discolored (red/purple), or itchy for more than 2-3 weeks. Or if the drainage from the piercing is a dark yellow/greenish color. It could just be irritated if its red and swollen. Go check with your piercer to be sure.
it is red
If your hampsters foot is swollen and its tail is red and curved you should take it to the vet.
Could be pimples, could be boils. Without further information it would be difficult to tell.