If it was toothache from a decaying tooth, surely the pain would be constant all the time right?

Tooth pain: A decayed tooth will be most sensitive to sweets, cold or hot things and this will vary depending on how healthy the nerve is. The decay alone does not cause the pain. The decay will allow the nerve to be exposed and stimulated by the things you eat and drink. Infection can set in and pain will increase. See a dentist and get your decayed teeth fixed before you have severe pain.

Possibly not!: While very often the pain from a toothache can be constant, intense and unrelenting, sometimes the pain is episodic. This is a result of the pressure from the disease/infection process being relieved by a fistula, minor swelling or thru a hole in the tooth itself. So it is possible to have a large cavity and even an abscess without pain. Just remember, pain or not, you need care!

Tooth pain, variable: Pain in and around the teeth is a common problem, particularly among patients with poor oral hygiene. The tooth pain could be intermittent with variable characteristics. Several dental conditions can also lead to serious and possibly life threatening complications. Call your dentist today!

Typical Progression: Early decay progresses though the tooth. Initially there is no pain. As the decay increases in size, the tooth becomes sensitive to cold & sweets. When the decay approaches the nerve, the nerve becomes inflamed & sensitivity to heat usually indicating irreversible damage requiring RCT. However there are no rules! Some patients only experience pain late in the game, others very sensitive early on.

No: It can come and go depending on the irritants -- sweet, cold, sometimes hot, chewing, etc. See the Dentist for examination and diagnosis and treatment, before it becomes constant and perhaps requiring root canal therapy or extraction. Go... Good Luck.

Not necessarily: Episodic pain is not uncommon with toothaches.