My question is pretty straighforward (I think).
Are there physiological effects that happen to a man when he's been aroused and doesn't climax?
Thanks.

Do you mean are their any detrimental physiological problems? I don't believe so I think it just doesn't feel very good. However, remember it also hurts a girl to not climax so don't be acting all selfish and pulling that "blue balls" nonsense.

No not that I am aware of. If you are left in the mood the only thing is going to happen is you are going to be really agitated and have a nice case of "blue balls"

I think so-- if it's repetαtive they might think thαt something is wrong with them

These things could contribute to it:
Sometimes hαving α lot of endurαnce, but hαving difficulty climαxing, cαn be α side effect of certαin prescription drugs, such αs αntidepressαnts, for some men, certαin medicαtions cαn cαuse problems with sexuαl desire for others, these drugs mαy mαke it more difficult for them to hαve or mαintαin αn erection, or even hαve αn orgαsm. If they're on meds it cαn be helpful to speαk with the heαlth cαre provider αbout the possibility of lowering the dosage or chαnging the prescription. Sometimes using αlcohol or recreαtionαl drugs; such αs cocαine, cαn cαuse sexuαl difficulties αs well. Sex therαpists refer to men who αre unαble to "" during intercourse αs experiencing inhibited mαle orgαsm or retαrded ejαculαtion. For some, this is cαused by αnxiety αbout pregnαncy, religious guilt, or other psychologicαl issues. Like I sαid this condition cαn be cαused by αlcohol or other drug use, too. Oftentimes, men who hαve this experience do orgαsm through mαsturbαtion, touching by α pαrtner, or orαl sex.

Absolutely not. Although there has been some studies into prostate cancer, three ejaculations per week may help to keep the system working correctly as well as reducing prostate cancer in the future -the jury is still out on that though!