a painful swelling on head

dental problems, lump or swelling in groin in males, lump or swelling on leg(s), lump(s) in skin

An abscess is a collection of pus that has accumulated in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e.g. splinters or bullet wounds). It is a defensive reaction of the tissue to prevent the spread of infectious materials to other parts of the body. ... 

a painful swelling in skin, blister(s) or bump(s) on skin, lump(s) in skin, redness in skin

Boil or furuncle is a skin disease caused by the inflammation of hair follicles, thus resulting in the localized accumulation of pus and dead tissues. Individual boils can cluster together and form an interconnected network of boils called carbuncles. In severe cases, boils may develop to form abscesses. ... 

difficulty walking, headache, poor coordination, vision problems

Head injury is a trauma to the head, that may or may not include injury to the brain (see also brain injury). ... 

fever, lump or swelling on leg(s), lump(s) in skin, swollen ankle

Cellulitis is an inflammation of the connective tissue underlying the skin, that can be caused by a bacterial infection. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, burns, insect bites, surgical wounds, or sites of intravenous catheter insertion. The mainstay of therapy remains treatment with appropriate antibiotics. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body. Cellulitis may be superficial — affecting only the surface of the skin — but cellulitis may also affect the tissues underlying the skin and can spread to the lymph nodes and bloodstream. ... 

a painful swelling in skin, blister(s) or bump(s) on head, lump or swelling on face, lump(s) in skin

A hematoma, or haematoma, is a collection of blood, generally the result of hemorrhage, or, more specifically, internal bleeding. Hematomas exist as bruises (ecchymoses), but can also develop in organs. ... 

fever, lump or swelling in groin in males, lump or swelling on leg(s), lump(s) in skin

a painful swelling in skin, bruises on face, lump(s) in skin, redness in skin