Lately my mouth tastes salty. It doesn't matter how many times I brush my teeth (and tongue) or what I eat or drink, the salty taste won't go away. Then all of a sudden it's gone. This has happened three or four times within the last few weeks. Can you tell me what causes this and if I should see my doctor?

N.S.

There are a few possible explanations for your problem. Before discussing these possibilities, I'd like to point out that a salty taste truly does originate in the mouth (or brain) -- the nose can be ignored in this discussion. This may seem obvious to you, but it's an important point. Smell and taste are inextricably intertwined, so many "phantom tastes" are, in fact, "phantom smells." The list of possible explanations for "phantom smells" is quite different. In your case, we can ignore these possibilities; a variety of odors can simulate sweet, bitter or sour tastes, but I do not know of any odors that simulate a salty taste.

So ... if your mouth is where the action is, what could this be?

1. The chemical composition of saliva may change in response to hydration. (In other words, are you drinking enough liquids?) If you are chronically dehydrated, you may have saltier saliva. Take a close look at what you drink. Some folks drink only caffeinated beverages and alcoholic beverages. Caffeine is a diuretic -- it makes you urinate -- so a steady diet of coffee, tea and caffeinated soft drinks will leach water from your body. Alcohol is even worse in this regard.

   The salinity (salt content) of saliva may also change in response to medications and salivary gland disease. A number of noninfectious and infectious diseases can afflict the salivary glands; examples of each, respectively, are Sjogren's disease and bacterial sialadenitis.
   

2. Postnasal drainage can often have an odor and a taste. Bacterial sinusitis, for example, can cause bad breath and a foul taste in one's mouth. I would not be too surprised if a patient reported this taste as "salty." Postnasal drainage secondary to nasal allergy (allergic rhinitis) might also be salty. Usually folks with postnasal drainage are aware of their condition. If you are not "full of mucus," then this is an unlikely explanation for your problem.
   
3. Tears are very salty. The tear ducts drain into the nasal cavity; once tears enter the nasal cavity, they drain down the back of the throat. (People constantly produce tears, by the way; you don't have to cry to have tears!) This is really unlikely, but perhaps you are overproducing tears.
   
4. Here's one more really unlikely possibility: Since sensation ultimately resides in the brain, the problem could be upstairs. Migraine, epilepsy and brain tumor all come to mind, but each of these would be exceptionally rare explanations for your problem.
   

Should you see a doctor? If your symptoms persist or worsen, or if your symptoms appear to be associated with other unusual symptoms, then YES, you should see a doctor.