Summarize this article:

If you know the person well and they've never had a seizure before, you should call emergency services to get immediate medical care. They can assist in stopping the seizure once they arrive. Even if the person has had a seizure before, you should call emergency services if the seizure lasts more than 5 minutes. Begin the timer as soon as you can get the person safe.  You should also call emergency services if the person injures themselves, has trouble breathing, has more than one seizure in a row, or has another health condition such as diabetes or heart disease. Also, call if the seizure happened in water or if the person is pregnant. If you are questioning whether or not you should call emergency services, give them a call. It is always better to call if you're unsure. If you're the only person there, it's important to stay with the person having the seizure so you can monitor them. Plus, they will be disoriented when they come out of the seizure, so they will need someone there. Try to stay calm and collected. Be sure to check the person for injuries as they come out of the seizure; look for blood or bruises. Keep in mind, they may not be able to answer questions due to disorientation.

Summary:
Call an ambulance if it's the first time the person has had a seizure. Call emergency services if the seizure lasts more than 5 minutes. Stay with the person.