Memory loss and concussions are from injuries to the head. Concussions should not be mistaken for other cerebral injuries such as bleeding under the skull or inter cranial. Concussions are simply diagnosed closed head injuries.
CONCUSSION TYPES: they can range from severe concussions to the head that lead to blackouts to milder cases that entail no loss of consciousness.
CAUSES: An impact of outer force applied to the skull can push the brain into a deep state of trauma. A major fall, car accident, or any other event that has a headlong collision with a foreign object are the most common causes.
SYMPTOMS: Vomiting, nausea, and unconsciousness are the first signs of a concussion. The victims vision may also blur. Because of all this confusion and disarray happens. When the victim is traumatized there is a lso a period of short term memory loss. The victim may even ask the same question over and over again even if it has been answered due to an experience known as persevering.
MEDICAL HELP, IS IT ALWAYS NECESSARY? Not always, say doctors. But it is still advisable that a medical professional is consulted in the event of such an accident. After that, it is the doctor’s prerogative whether to advise simple bed rest and homecare, see the patient individually or to recommend immediate hospitalization.
SITUATIONS THAT DO NOT REQUIRE ICU: When a person impacts something hard like tile or bathtub floor, and the patient remains conscious and only suffers mild nausea and dizziness and no loss of vision. The worst they may suffer from is a headache for a couple days. Even if memory loss occurs it is no reason to panic.
SITUATIONS THAT REQUIRE THE AMBULANCE: memory loss from concussions can be irreversible if they are not take care of quickly. Special cases where an ambulance is needed are when the victim remains unconscious for over 2 minutes. The victim falls from a great height. The victim has severe physical weakness and bouts of vomiting.
source: http://www.xtremeus.co.cc/health/concussions-cause-short-term-memory-loss/