Many causes. Most white spots are either from irregularities in the enamel of your teeth or from decalcification caused by decay-producing bacteria. See your family dentist. There are many good ways to make white spots less visible.
Many possibilities. There are many possibilities as to what they are and there are many methods to remove them. See a dentist to determine exactly what they are and then discuss your available treatment options.
Decalcifications. Acid reflux could cause the white spots while many foods and or medications can stain the enamel.
Look to your habits. Spots or stains on adult teeth that weren't there before are usually a result of what you eat or drink. White spots means the enamel is being attacked. Do you drink lots of soda or acidic drinks or suck on lemons. That'll do it. As for stains...Drinking dark sodas, coffee, tea or wine are the most common sources of stains. Also...How is your oral hygiene? You need to help the situation.
White spots. You may or may not be able to however the only way to find out is to see your dentist for an evaluation.
Fluorosis. They are called fluorosis and they are really changes in the mineral composition in the enamel. Sometimes they are there naturally sometimes you get them after you have had braces placed again because of changes in the mineral composition of teeth.
Demineralization. White spots are areas of the teeth that are missing some of the minerals in the teeth. This can occur when the teeth are developing and enter the mouth. Some areas of the country have too much flouride in the water and in the early stage of flourosis the teeth will be white before the turn brownish.