Although vomiting is often a sign of nothing more serious than a mild case of food poisoning or a stomach virus, there are certain situations in which emergency care is necessary. The most basic benchmark is four to five hours of uncontrolled vomiting and the inability to keep clear fluids in the system. In such a situation, a patient is at risk of dehydration and is likely to require intravenous fluids.
Patients are also likely to have an emergent condition if they are vomiting blood. Even a small amount of blood in the vomit indicates that something serious may be occurring internally. Bloody diarrhea is similarly concerning, although non-bloody diarrhea co-occurring with vomiting may also indicate a more serious issue.
In addition, doctors may recommend that a patient seek out emergency care if he or she is having severe stomach pains, headache, or confusion along with the vomiting. Relatedly, any patient who has had a head injury within the prior 24 hours could be at risk of concussion and may need medical attention immediately.
Parents of young children may wish to be particularly conservative in deciding whether to seek out emergency care for vomiting. Children under the age of six months are particularly at risk of dehydration, just as fever may be more dangerous for the very young.
Whether the patient is a child or an adult, conservative decisions are often the wisest. If there is any doubt as to the necessity of medical care, it tends to be safer to seek out that care than to wait out a potentially dangerous situation.