choke up

choke up  {v.}

1a. To come near losing calmness or self-control from strong feeling; be upset by your feelings.

When one speaker after another praised John, he choked up and couldn't thank them.

When Father tried to tell me how glad he was to see me safe after the accident, he choked up and was unable to speak.

1b.  {informal}

To be unable to do well because of excitement or nervousness.

Bill was a good batter, but in the championship game he choked up and did poorly.

2. To fill up; become clogged or blocked; become hard to pass through.