Tick are tiny insect that bit to feed blood of warm blooded animals including humans.Tick also can cause skin reaction like lumps and granulomas. Also fever and paralysis can occur after a tick bits you.

Another is that tick are infected with bacteria and viruses.They can transfer it to there host (animal or human) by feeding...And when they feed on there host blood, they cause disease.

Unfortunately it will surely swell...It's because the tick just suck your blood.

What you should do is to have a check up!