Hillary Clinton’s wobble Sunday at the 9/11 ceremony has been the talk of the news cycle, and once her camp put out the word that she had been diagnosed with pneumonia there’s been a great deal of speculation about the likelihood of that.

Here’s a summary of the medical announcement Clinton’s doctor made:

Clinton has had an allergy-related cough for some time, and during an examination on Friday, the Democratic nominee was diagnosed with pneumonia, put on antibiotics, and told to take time out to rest. She became overheated and dehydrated during Sunday morning’s event, which led her to collapse. She’s now home in Chappaqua and on the road to recovery.

We have no way of knowing if this is true or another lie. Only a doctor who has examined Hillary Clinton and done the appropriate tests could answer that question. But let’s take a look at some possibilities.

First, it’s important to differentiate between her chronic and acute symptoms. Clinton has been observed to have had a chronic cough for some time, one that’s been exhibited during the campaign and remarked upon frequently. The thing about a symptom such as chronic cough is that it can come from a very wide variety of causes, some quite common and some rare. The causes can also be difficult to diagnose and to differentiate from each other. But if you follow that link you can see that the causes that are highest on the list are relatively innocuous: postnasal drip or asthma (which are often allergic in nature) and GERD (gastroesophageal reflux), a very common problem. One of those two reasons is certainly likely to be the culprit, just in terms of their incidence in the general population as a cause of chronic cough.

Then there are Clinton’s more acute symptoms on Sunday: the wooziness and the wobbly legs. Pneumonia plus dehydration? Certainly possible; the symptoms of dehydration include weakness, dizziness, confusion, and fainting.

Most people would probably rest if they had pneumonia, although there is a variant of the illness popularly known as “walking pneumonia,” in which people feel well enough to be out and about—at least for a while. A presidential candidate would certainly have every reason to act more energetic than he or she actually feels, especially if that person were trying to dispel persistent rumors of ill health and physical frailty. Then the illness could catch up with the candidate if the schedule is arduous.

That might easily have happened. Or it might be something much worse. With Clinton’s history of lying, the latter possibility cannot be discounted. But a fairly innocuous pneumonia is also consistent with the scenario that played out on Sunday, and Hillary’s more chronic cough symptoms could easily have been unrelated.

Pneumonia is a common illness both in its viral and bacterial forms, and occurs in all age groups although it’s most common in children under five and adults over 75. It can be relatively minor or very deadly, or almost anything in-between. It’s unclear from the announcement whether Clinton is alleged to have the viral or bacterial form, and I doubt it matters all that much in terms of the political consequences of the story. Clinton was given antibiotics, which indicates it was more likely bacterial pneumonia, and a person with bacterial pneumonia is no longer considered contagious after taking the antibiotics for a day. But it is my understanding that sometimes antibiotics are given as a preventative against a bacterial overlay even when someone has viral pneumonia.

There was a Powerline piece Sunday that quoted a doctor who has not examined Clinton but who speculates that Clinton may have aspiration pneumonia caused by a swallowing problem from a neurological disorder such as Parkinson’s:

Aspiration pneumonia occurs when fluids and food particles that normally enter the esophagus instead enter the windpipe and lungs. It is commonly seen in neurological conditions like strokes and Parkinson’s disease or similar diseases where the nerves to the swallowing mechanism are not working properly. This is especially worrisome because it is likely to recur given the underlying, usually incurable disease process and because it can be a life-threatening event.

This is pure speculation; there’s no reason to think Clinton has aspiration pneumonia, because the other types are far more common. However, even though aspiration pneumonia is not what you’d call extremely rare (about 15% of pneumonia cases in the US are of this type), either, it still does not necessarily indicate a serious problem or a neurological one. A significant number of cases of aspiration pneumonia occur in normal people who do not have any neurological impairment whatsoever:

Aspiration pneumonia can also be associated with esophageal disorders, anesthesia, and dental problems that interfere with chewing or swallowing. Sometimes, the swallowing muscles can become weak with age or inactivity, for example, a patient who is on mechanical ventilation for several days or longer. Aspiration can occur in these situations as well. Finally, persons with normal swallowing and a normal gag reflex can aspirate and develop pneumonia if their food or drink simply “goes down the wrong way.”

We can all agree that Clinton isn’t on a respirator. But she certainly could have an esophageal disorder, which could also account for her chronic cough. Ten to twenty percent of people with GERD (and GERD is very common) have aspiration, and some of these cases go on to become aspiration pneumonia.

We may find out a bit more, because Hillary’s spokesman Brian Fallon has announced that her campaign would release more medical records this week. I doubt that the release will clear up the speculation as to what’s really going on, even if a diagnosis of pneumonia is revealed. There is too much reason to distrust that Clinton is telling the whole story, even if she finally does appear to come clean in this particular situation.

[Neo-neocon is a writer with degrees in law and family therapy, who blogs at neo-neocon.]