Differential Diagnosis for Head Injury with Nausea

The patient's symptoms of hitting her head and experiencing nausea without vomiting suggest a range of possible diagnoses. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Concussion: This is the most likely diagnosis given the mechanism of injury (hitting her head) and the symptoms of nausea. A concussion is a type of traumatic brain injury caused by a blow to the head or body, a fall, or another injury that jars or shakes the brain inside the skull.

• Other Likely Diagnoses

  • Cervical strain or whiplash: If the patient's head was jerked forward or backward during the incident, she might have strained her neck muscles, leading to nausea and discomfort.
  • Scalp laceration or hematoma: Depending on the severity of the impact, the patient could have a cut or a collection of blood under the scalp, which might cause nausea due to pain or blood loss.

• Do Not Miss Diagnoses

  • Subdural or epidural hematoma: Although less common, these are serious conditions where blood collects between the brain and the skull. Symptoms can be similar to a concussion but require immediate medical attention to prevent severe brain damage or death.
  • Skull fracture: A fracture could lead to nausea and potentially more severe complications if it affects the brain or leads to an infection.
  • Post-traumatic seizure: While not immediately apparent, the risk of seizure after a head injury is a critical consideration, especially if the patient loses consciousness or exhibits unusual behavior.

• Rare Diagnoses

  • Arteriovenous malformation (AVM) rupture: An AVM is a tangle of blood vessels in the brain that can rupture and bleed after a head injury, leading to severe symptoms.
  • Meningitis: Although rare, head trauma can potentially introduce bacteria into the meninges, leading to infection and severe illness.

For the ICD-10 code, a concussion would be coded as S06.0X0A (Concussion without loss of consciousness, initial encounter). However, the final diagnosis and coding should be determined by a healthcare professional after a thorough evaluation.