Sometimes doctors are faced with symptoms that remain unexplained despite extensive testing. When no clear medical explanation is found and symptoms persist, patients often progress anxiety and/or depression as a result of living with unresolved health problems.
In such cases, treatment often focuses on the emotional consequences, while the underlying medical mystery remains unsolved.
Sometimes, though, asking the right question can reveal a surprisingly simple explanation—and an equally simple solution.
Case study: chronic cough
Linda was 54 years old when she came to me with a persistent dry cough that had lasted for 14 months.
Cough during the day was relatively light, but at night it stopped. She described the constant sensation in her throat. A cough would briefly relieve the sensation, but within seconds, the hijab would return and produce another cough.
She tried drinking cold water, hot water, and various home remedies, but nothing provided lasting relief. A chronic cough disturbed his sleep night after night and made him sleepy during the day.
As the months passed, Linda became increasingly anxious and depressed.
Aside from her cough and treatment for high blood pressure, she was healthy, exercising regularly and eating a balanced diet. diet.
Linda was a never smoker and had no history of asthma. Her physical examination was normal. Blood tests and chest x-rays were unremarkable.
Over the past year, she has consulted several specialists.
An ear, nose and throat (ENT) specialist performed a laryngoscopy to investigate the sore throat but found no abnormalities. There was no inflammation and no evidence of postnasal drip.
A doctor suspected gastroesophageal reflux disease (GERD), thinking that stomach acid might be irritating his throat at night. Linda was prescribed a proton pump inhibitor for three months, but her symptoms did not change.
Concerned about the possibility of early lung cancer, another doctor ordered a chest CT scan. The scan was normal.
14 months after the cough started, Linda was still suffering.
Since there was no explanation and his anxiety and depression were getting worse, he wanted to see a psychiatrist when he came to me.
The question that solved the mystery
The most important question turned out to be surprisingly simple:
“What medications are you taking?”
When I reviewed Linda’s medications, I discovered that she was taking an ACE inhibitor to treat her high blood pressure.
Suddenly everything made sense.
It was a possible culprit medicine himself
What the research shows
Linda’s experience is unique.
ACE inhibitors (angiotensin-converting enzyme inhibitors), a broad class of blood pressure medications, are known to cause a chronic dry cough in about 5 to 25 percent of patients. Side effects seem to be more common in women and non-smokers. Coughing may begin shortly after starting treatment, but it may appear months or even years later. (1) (2) (3)
The simplest way to confirm the diagnosis is to stop the ACE inhibitor and switch to another class of blood pressure medication. In most patients, the cough improves within days to several weeks. If the offending drug is restarted, the cough often returns. (4)
Interestingly, these side effects are usually not dose dependent. Even low doses can cause cough in genetically susceptible individuals. (5)
Studies show that ACE inhibitors lower the cough reflex threshold in susceptible patients. As a result, simple environmental triggers that would not normally trigger a cough can suddenly trigger persistent symptoms. (6)
What happened to Linda?
I stopped Linda’s ACE inhibitor and replaced it with a calcium channel blocker, another class of blood pressure medication.
Within a week, her cough was gone.
For the first time in over a year, she was able to sleep through the night. As her sleep improved and her physical symptoms resolved, her anxiety and depression gradually disappeared—without the need for mental medicine
His blood pressure was well controlled.
Psychological lesson
Linda’s story illustrates an important principle in both medicine and psychology.
When symptoms remain unexplained, it can be tempting to focus only on treating their emotional consequences. However, anxiety and depression are often understandable reactions to persistent physical symptoms. Whenever possible, it is important to not only treat the effects, but to identify and eliminate the root cause.
Doctors should review all prescription drugs, over-the-counter products, and supplements before concluding that a symptom is unexplained or untreatable. Sometimes the answer is hidden in plain sight.
All over me careerI have encountered numerous patients with chronic dry cough who were treated with allergy medications, reflux-reflux therapy, and other measures, while the underlying cause—the ACE inhibitor—was ignored. In some cases, the drug was hidden inside a blood pressure pill, making it even easier to ignore.
Medicine is both science and art. Laboratory tests and imaging studies are invaluable tools, but careful listening and careful questioning remain just as important.
Sometimes the key to solving a medical mystery isn’t ordering another test—it’s another question.
Copyright 2026 @Chris Gilbert, MD, Ph.D.
