I have a small lump on my left wrist from hitting it. i can bend it but it is a little sore and is painful to touch. my wrist is bruised.

Bruise: could be a small blood collection if the injury is recent and should resolve in about 2 weeks. if not better in that time the se your doctor.

Hematoma: You likely have a small collection of blood under the skin called a hematoma causing this lump. I would only be concerned if any symptoms persist beyond 10 days. Ice for 15-20 minutes 2-4 times/day and relative rest can alleviate some soreness.

Bruise or fracture?: This is likely a simple bruise and your symptoms can be explained by inflammation that usually follows such an injury. However it is hard to rule out a fracture without getting an X ray so if you have ongoing pain, see your doctor please