Brief Answer:
It is not dangerous, and it is preventable.

Detailed Answer:
Hello

Welcome to Health Care Magic.
My name is Dr Muhammad Ahmad & i will look into your problem.

I have gone through your query and would try to help you in the best possible way.

My opinion:
According to the history you gave and your description about the swelling, in my opinion this isn't a dangerous thing and it is very preventable.

What it seems to be:

At your temple there is a muscle attached, which is named as Temporalis , this muscle is used in chewing and pulls the jaw up.
If you place a hand at your temple and clench your teeth tightly you can feel this muscle contracting and swelling up under your hand, this muscle ends exactly where you described the swelling being present.
The problem happening to you is a very common problem, in heavy weight lifters and meth abusers, because they do one thing in common and that is, clenching their teeth very tight repeatedly. If you reflect back on your work out today you will realize that you have this habit of clenching your teeth while you lift heavy, this causes the muscle to contract very strongly, more than it should, so muscle fibres get soar and fluids start oozing out of them, in addition to muscle fibres, surrounding tissues also get inflamed due to strong contractions of muscles outside the safe limits,fluids ooze out which create a swelling at that place, but with time, body re-absorbs extra fluid back to the blood and swelling disappears. It's possible that you have what's called, "delayed onset muscle soreness".

SUGGESTIONS:

1- Simplest solution is to avoid clenching when you lift heavy, it's hard when you have a habit of it, but one can learn with active effort.
2- Some weight lifters wrap tight XXXXXXX or bands around their temples encircling their head specially putting pressure on the area which has problem, and many have reported that it helped.
3- But if you still get that the swelling some day, don't panic, it's not a dangerous condition just massage the area with some anti inflammatory cream if you fell like other wise wait for it to resolve.
4- Warm compresses on the swelling make it to resolve more quickly.
5- Some health expert advocate post work out stretching of jaw if you know you have clenched your teeth too much through your lifting. Effectiveness of this maneuver is debatable but doing it has no contraindications.

I hope your issue will resolve if you work on my suggestions.

Hope I have answered your query. If you have any further questions I will be happy to help if not then don't forget to close the discussion and rate it.
Wishing you good health !!

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