Strangling in a dream is connected to holding back words in waking life. If someone is strangling you then you may be feeling pressured to keep quiet about something or someone around you may be trying to control you to the point you that you can’t speak up about it. Your dream is showing you that not speaking up or voicing your thoughts is harmful to you.
If you are the one doing the strangling you should still look at yourself first and ask yourself if you are keeping yourself from speaking up about something. Otherwise, ask yourself if you have been keeping someone else from voicing their opinions. Are you the type that does not allow others to speak their mind? Do you talk over others?
If you frequently dream of choking or strangling and wake up unable to breathe, you may want to get checked for Sleep Apnea as waking up choking is a common symptom.