I'm 35 and have had well over 20 cat scans. what is my potential cancer risk?

Very little : Current ct scanners are fast sophisticated emits negligible amount of radiation to cause you harm . But have to worry about your condition that required 20 cat scans, speak to your doctor take care of that condition

Very little, if any: Medical use of x-rays is considered safe. So i would not think too hard about it now that you have already gone thru them. But slow it down for the future, as there are always alternative imaging tests which can be used instead of ct scans. Just be more proactive and express your concern to the ordering doctor in the future.

No one knows for: Sure. Depends on many factors- some scan related (kvp and ma on scanner, length of scan), type of scanner, number of phases in each scan. Other factors: what body part(s), how often scans happened (time between scans to allow for genetic repair) and the personal genetics of the patient. A rough estimate can be created if details about each scan are known. Other ?S why so many and did it help.