The needles used are sterile, solid and extremely fine and each needle is only used once. It is usual to feel a mild pricking sensation as the needle pierces the skin, and a sharp pain as the needle is engaged (twiddled) but once the needle is in position patients usually report an aching or warm sensation. It is unusual for the needles to be uncomfortable when in situ. Occasionally there is a tiny droplet of blood when the needle is removed but generally there is none. Some patients report feeling like the needle is still in after treatment – this feeling generally disappears within an hour.