The short answer
For severe allergic symptoms, get emergency help: dial 911 or head for the emergency room closest to you.
Signs of a severe allergic reaction
MedlinePlus, a health resource from the National Library of Medicine, lists breathing trouble, trouble swallowing, a swollen tongue and fainting among the signs.
A severe allergic reaction is called anaphylaxis; its symptoms can appear within seconds or minutes.
The list cannot diagnose what is happening to a particular person.
An infection can also become an emergency
Sepsis means an extreme response by the body to infection. The Centers for Disease Control and Prevention names it a medical emergency.
That agency lists confusion, severe pain, clammy skin and shortness of breath among the possible signs.
These are signs to take seriously, rather than a way to diagnose the cause yourself.
Keep the medicine details available
If you are seeking help about a medicine, bring its name and the information supplied with it when possible. Describe what happened and when it began. Ask the person assessing you what information would be useful.
After the immediate concern has been addressed, patients can also report a suspected medicine problem to the Food and Drug Administration (FDA).
The agency’s reporting programme is called MedWatch.
Carry this forward
For severe allergic symptoms, the next step is emergency help.