I hit my hand, and now my 4 fingers are swollen, and bruised. what is the cause? does low iron cause this?

Maybe normal: It's difficult from your description to tell what part of your hand may be swollen. It's possible there could be damage to nerves or blood vessels, causing swelling "down stream" in the fingers. Seek urgent evaluation if discoloration, numbness or worsening pain. Otherwise see PCP ASAP. Hard to say if low iron is involved.

Hard to say: It could be from as simple as local trauma to the soft tissue and resultant inflammation and small blood vessel damage to more concerning damage to the underlying bones. It's most likely the former but if you are really concerned seek an inperson evaluation. In the meanwhile consider using some ice packs and elevating your injured hand. Iron deficiency is unlikely a contributor. Best of luck.

Not per se: How long ago did you hit your hand? Were all the swollen fingers injured? Do you have a tendency to bleed on minor cuts? If the swelling and bruising has persisted for more than a couple of days, you should see a doctor to exclude fracture. Iron deficiency by itself would not explain your symptoms.

Hurt, not iron: If you hit your hand hard enough to cause bleeding inside, the blood will follow gravity and so will the bruise. Fingers may swell also. Not related to iron levels. Elevate your hand, wrap it with ace and wrap fingers with Coban if needed. Don't use ice or NSAID's. Apply cream or jell with Arnica in it. Give it a couple weeks to heal. www.blatmanhealthandwellness.com