If you fall hard on your back and have a headache and nausea shortly afterward, the most likely reason is that you hurt your head during the fall and that caused a concussion. However, it is also possible that another, slightly different injury is causing these symptoms; visit your doctor for a correct diagnosis.
Both headaches and nausea are common symptoms of a concussion. A concussion may also be accompanied by confusion or amnesia, dizziness, hearing a ringing sound, inability to speak clearly, feeling pressure in the head and tiredness. Some time after the concussion occurs, the patient might notice difficulty tasting, smelling or sleeping normally; elevated sensitivity to bright lights and loud noises; and irritability.
Although a blow to the head is the most common cause of a concussion, falling without hitting your head could also cause one. A concussion occurs when the head moves so sharply that the brain crashes into the interior of the skull. Under normal circumstances, the brain is cushioned from this type of impact by the protective fluid in which it is suspended; a sudden impact or heavy fall, however, could create enough trauma to affect the brain, causing a concussion.
Seek medical treatment if you think you may have suffered a concussion. Your doctor can determine the severity of your injury and its optimal treatment. In most cases, you will need to rest and avoid any activities that could aggravate the injury. Your doctor may recommend acetaminophen to treat the headache; the Mayo Clinic recommends that you avoid most other pain medications since they could increase the bleeding risk.
Other Possible Causes
It is also possible that you suffered a different injury in your fall that is causing the headache or nausea as secondary symptoms. For example, an injury to the neck could be accompanied by a headache, according to the American Association of Neurological Surgeons. You could go into shock after a serious fall, which could cause nausea, vomiting and similar symptoms. Regardless, seek help from a doctor as soon as possible after the injury.