Welcome to the forum.
According to your description , pain and swelling over your hand, wrist and forearm seems to be inflammatory in nature.
I advice you to give you rest to the part affected, take anti-inflammatory drug like motrin
1 tablet with food as and when required (upto 4 tablets daily) to reduce pain and inflammation and consult your doctor for thorough examination and rule out any infective cause.
Tests (also known medically as Investigations) include X-rays, scans, blood tests and particularly in the hand electrical tests (known as EMGs or Neurophysiology). These may be used to help make or confirm a diagnosis after a patient has described their symptoms and been examined.
Wishing you good health...
I hope this is helpful to you.
You can consult me again directly through my profile http://www.healthcaremagic.com/doctors/dr-saurabh-gupta/64132
Dr Saurabh Gupta.