Osteoarthritis (OA) is the most common degenerative joint disease found in the elderly. Drug options that are recommended by the American Academy of Orthopaedic Surgeon (AAOS) are acetaminophen, NSAIDs, tramadol, capscaicin and intraarticular corticosteroids. However, there is concern for the possible side effects resulting from long term use of those medications. Researchers are searching for a safer treatment modality for OA. Leech therapy (hirudotheraphy) is one of the therapies under investigation, given its purported analgesic and antiinflammatory properties.