What is the difference between the pain caused by tooth decay, sensitive teeth and sinus pain?

Go see your dentist: You need to note whether it is sensitive to cold or hot and if it lingers for more than ten seconds. A small tooth decay usually is sensitive to cold but as the decay gets deeper the tooth can also be sensitive to hot and lingers for a while. Sinusitis can also cause toothache but usually it is hard to pinpoint to a tooth. Sometimes the whole back teeth are sensitive when you have sinus infection.

They feel different: Sinus pain can cause tooth pain but it usually covers broad areas, usually around back upper teeth. Sensitive teeth normally respond to hot or cold or sweet and quit hurting quickly when the irritant is removed. Tooth decay pain can feel like either of the other two, it is localized to a particular tooth and can be unrelenting and if it does fade it will do so more slowly than just sensitivity.

Similar: Pain from tooth decay is dependent on the amount of decay. If you are only getting sensitivity from the decay you are only causing dentin irritation. Sensitive teeth are sensitive by a similar mechanism. Both situations are from changes in osmotic pressure of the dentinal tubules. Sinus pain when felt in teeth is kinda like phantom limb pain. Pressure on the nerves that wire the teeth.

A bit tricky: These 3 causes of pain can be a bit tricky to sort out sometimes. If tapping on the suspected tooth increases pain, then it is probably the tooth. Sometimes a troubled tooth causes sinus problems. Sometimes the maxillary sinus (one under your cheek bone) problem causes enough pain to feel like it's in the upper teeth. So, it is best to see your doctor and/or dentist to help sort it out.

See A Dentist: See a dentist, as there are some evaluation methods that can be used by the dentist to determine what is causing your pain.

Yes: Sensitive teeth are usually caused by exposed dentin and can happen in any tooth. Not that intense and goes away as soon as the offending source (like a cold drink) is removed. Tooth decay when it gets close to the nerve will cause more intense pain and will come and go on its own in addition to reacting to stimuli. Sinus pain often feels like a toothache - only on upper teeth usually molars.