This was not the diagnosis listed on the discharge sheet. In this case, Katherine was lucky. Eventually her HMO did agree to cover this bill, but only after several appeals. A discrepancy between the patient's worst possible diagnosis and the actual diagnosis is a common cause for denial of payment for emergency room visits. Abdominal pain from a viral infection can mimic appendicitis, but HMOs only consider one of these an emergency.
Dizziness can be a symptom of a stroke or an inner ear infection.
Again, a lay person can not tell the difference, but delaying treatment for the stroke could be life threatening. A child with a high fever and a headache could have flu, strep throat or meningitis. Flu isn't an emergency. They get angry. They try to find someone to blame.