New Delhi: Oral health can tell you about your overall health and well-being. Weak teeth, cavities, staining and teeth sensitivity are common problems faced by many.
Out of all these tooth sensitivity can be a pain in the-well, in the mouth. Cold or hot foods and drinks, sugary sweets, even a c old wind against your teeth can make your pearly whites start throbbing or stinging.
In most cases, teeth are sensitive because their protective outer layers-enamel over the crown, or cementum over the root-have worn away. That exposes your tooth’s dentin, which is full of tiny tubes with sensitive nerve endings running through them.
Causes for Tooth Sensitivity:

1. Brushing too hard (‘toothbrush abrasion'), and brushing from side to side, can cause enamel to be worn away - particularly where the teeth meet the gums. The freshly exposed dentine may then become sensitive.
2. Dental erosion: this is loss of tooth enamel caused by attacks of acid from acidic food and drinks. If enamel is worn away, the dentine underneath is exposed which may lead to sensitivity.
3. Gums may naturally recede (shrink back), and the roots of the teeth will become exposed and can be more sensitive. Root surfaces do not have an enamel layer to protect them.
4. Gum disease: a build-up of plaque or tartar can cause the gum to recede down the tooth and even destroy the bony support of the tooth. Pockets can form in the gums around the tooth, making the area difficult to keep clean and the problem worse.
5. Tooth grinding: this is a habit which involves clenching and grinding the teeth together. This can cause the enamel of the teeth to be worn away, making the teeth sensitive.
6. A cracked tooth or filling: a cracked tooth is one that has become broken. A crack can run from the biting surface of a tooth down towards the root. Extreme temperatures, especially cold, may cause discomfort.
7. Tooth bleaching: some patients have sensitivity for a short time during bleaching or afterwards. Discuss this with your dental team before having treatment.
Not So Known Reasons for Tooth Sensitivity:
1. Sinus: People who suffer from sinus getting a dental infection or even suffering from teeth sensitivity is common. This is because the sinus lies close to the floor of the teeth and so a sinus that flares up with a bad cold can lead to a headache, jaw pain or teeth sensitivity.
2. Menstruation: Menstruation gingivitis is a common oral problem that women go through but hardly know about it. This happens due to hormonal fluctuations during the course of menstruation or days before you get your period.
3. Pregnancy: Hormonal fluctuate on during pregnancy is common. It does a lot of things to your body and one of them is making your teeth sensitive. I changed three kinds of toothpaste during my second pregnancy and I don’t have a tooth problem otherwise.
4. Bruxism: People who suffer from bruxism or teeth grinding at night also suffer from teeth sensitivity as it erodes the enamel and makes them susceptible to it.
5. Stress: Probably stress doesn’t contribute to teeth sensitivity directly but there are studies that say psychological stress appears to contribute to poor oral health systemically in combination with other chronic diseases. Moreover, stress is also a precursor of Bruxism which could make your teeth sensitive.
6. Cold weather: You might have also noticed it that the cool weathers actually gives your gums an unusual sensation and makes your teeth sensitive during the winter months.
What to do to Avoid Sensitivity? 
1. The quickest and easiest way would be to switch to specialised toothpaste formulated to take care of sensitive teeth.
2. Change your brushing habits. If you’re not using a soft toothbrush and if you’re scrubbing your teeth vigorously, you might worsen the condition. Hard-brushing can wear away the enamel, increasing sensitivity of teeth.
3. Keep a check on acidic food and drinks as they might wear down the enamel. Limit their consumption, and try to brush about 20 minutes after eating (not earlier, or the brushing may hurt your enamel further).
4. Teeth-whitening treatments or alcohol-based mouthwash can make things worse, so steer clear of them.
5. In case your problem continues, you must visit your dentist.
6. Individuals with gastric problems or gastric reflux should be treated with appropriate antacids, as acid reflux can lead to demineralisation resulting in dental enamel erosion.
7. People who have par functional habits such as teeth clenching or bruxism are advised to wear a night guard.

Methods to Relieve Tooth Pains:
1. Strengthen Your Enamel. Don't abandon your enamel. ...
2. Preventive Care, Preventive Care, Preventive Care. Sensitive teeth are a sure-fire sign that something is amiss in your mouth. 
3. Guard Against Tooth Pain. 
4. Chew Gum.
5. Fluoride Rinse. 
6. Skip the Whitening Treatment.
7. Sensitive Toothpaste.

References:
https://www.dentalhealth.org
http://www.hindustantimes.com/
http://www.thehealthsite.com
http://www.besthealthmag.ca