a. Tooth pain that may be sharp, throbbing, constant, sporadic, mild, moderate or severe*.  Pain can also result only when pressure, cold or heat is applied to the tooth.   

b. While decay often is cited as the primary cause of a toothache, it's important for you to have a complete oral examination to determine the cause. Other dental causes of a toothache include: infection, gum disease, clenching or grinding teeth (bruxism), tooth trauma and an abnormal bite. In babies and school-age children tooth eruption may be the cause of tooth or jaw pain .  

c. Temperomandibular Jaw Dysfunction (face, jaw or ear pain), sinus or ear infections can cause discomfort that resembles a toothache, but often these health problems are accompanied by a headache. Pain around the teeth and the jaws can be symptoms of heart disease such as angina. If your dentist suspects a medical cause he or she may refer you to a physician. 

d. Treatment for tooth pain varies dependant on the cause of the tooth pain.  However, a appointment for an accurate diagnosis would be needed so the cause and treatment options can be explained to you.  Also important to note is that if there is a large cavity, the tooth may require root canal treatment to be followed up with a post and core and a crown.

* I find it helpful for a person to describe the degree of pain using a scale of 0 – 10 with 10 being really bad pain

Sensitivity to cold and pressure usually is caused by excessive pressure against a tooth because or from excessive clenching or teeth grinding.  Treatment for this may be as simple as adjusting the bite to reduce the pressure against the sensitive tooth. 

Another possible cause of sensitivity can be a crack in the tooth.  It is interesting that if cracked piece of the tooth breaks off the sensitivity generally stops.

Strong pain to heat lasting 15 second to a few hours usually is due to an infection in the nerve.  The treatment for this is root canal (Endodontics).

Sensitivity to cold or touch can occur on the tooth or root surface where   the gum is receded.  Treatment for sensitivity includes desensitizing agents, desensitizing toothpastes, and the placement of white fillings.  A bite adjustment to the tooth or teeth with sensitivity may also be recommended.

Teeth can break for a number of reasons. 
         a. Excessive force from clenching or grinding
         b. Biting into something hard like a piece of bone
         c. A tooth with root canal that is not properly supported by a crown
         d. A tooth with too large a filling for the remaining tooth to support
         e. An accident or a fight

The treatment needed to fix a broken tooth depends on how much of the tooth is broke.  Treatment can be just smoothing of the broken edge to a tooth, a filling, a crown or possibly root canal treatment and a crown.