Why lying to your doctor is a mistake according to Dr. Gérald Kierzek: these silences that harm your health

Why lying to your doctor is a mistake according to Dr. Gérald Kierzek: these silences that harm your health
Alcohol, tobacco, supplements, forgotten treatments… Dr Gérald Kierzek reminds us that these omissions are not used to judge the patient: they can distort medical interpretation and treatment.

Do you minimize a drink, forget a supplement or don’t dare say that a treatment has been stopped? The answer is simple: these omissions can really direct care differently. In the show “The advice of Doctor Kierzek” on ICI, broadcast on September 30, 2026, the emergency doctor and medical director of True Medical explains why speaking frankly helps you receive better care.

Alcohol, tobacco, treatments: omissions that confuse the consultation

Dr. Gérald Kierzek recognizes that “small accommodations with the truth” rarely concern a single subject: they often touch on what can embarrass, shame or give fear of being judged.

He cites several pieces of information that patients may downplay or gloss over:

  • Alcohol consumption presented as occasional, without specifying the quantity or frequency;
  • Hidden smoking or reduced to “just in the evening”;
  • An embellished diet or overestimated physical activity;
  • An intimate life that is difficult to approach: partners, sexually transmitted infections, sexual disorders;
  • Drugs, including cannabis, non-prescription medicines or food supplements;
  • A chronic treatment forgotten, modified or stopped without reporting it.

The point is not to draw up a list of mistakes. Embarrassment and fear of judgment explain part of these silences. But, as the doctor points out, the consultation is not an examination where you receive a note: it serves to gather the right information to understand a situation.

False information can change medical interpretation

Dr Kierzek insists on this point of the doctor-patient relationship: the doctor “is not there to judge”, nor to give a moral lesson. On the other hand, he cannot reconstruct with certainty what is not said.

“The doctor cannot guess everything.”

Concretely, alcohol and tobacco can influence certain biological resultsdepending on the type of analysis, the quantity consumed and the time before sampling. Mentioning them avoids interpreting a result out of context.

Tobacco is also useful when a wound heals poorly: Dr. Kierzek points out that it can be a factor in poor healing. If the patient says he does not smoke, the doctor may look for other explanations and lose information useful for treatment.

Another example given in the column: food supplements, even so-called “natural”, can be active. Health Insurance reminds that certain products, drinks, tobacco or non-prescription medications can modify the effectiveness or adverse effects of a treatment. St. John’s Wort, in particular, can reduce the effectiveness of several medications, including the contraceptive pill. This is why mentioning food supplements to your doctor is a useful reflex.

The same logic applies to observance. For chronic treatments, the WHO estimated in 2003 that on average only one in two patients follows their long-term treatment correctly in developed countries. This does not concern all one-off prescriptions, but shows the issue: if cholesterol treatment is stopped without saying so, the doctor may be led to think that it is insufficiently effective and to reassess the treatment. Talking about a stopped or forgotten treatment helps avoid this misunderstanding, without deciding to change it alone.

Before the meeting, prepare a simple list and speak without shame

Dr. Kierzek’s practical advice is very concrete:
come with the list of everything we take. It can include current prescriptions, medications purchased without a prescription, dietary supplements and anything that has been discontinued or forgotten.

This list doesn’t need to be perfect. It is mainly used to avoid forgetting a product taken occasionally or stopping treatment that is difficult to admit. If a question concerns contraception, a chronic illness, intimate pain, cannabis use or an adverse effect, the right reflex remains the same: tell the doctor or pharmacist so that the information is included in the decision.

Dr. Kierzek also reiterates a reassuring point: the information entrusted to the doctor is covered by medical confidentiality. In France, they are not communicated to the employer and are only shared with relatives or other professionals in cases regulated by law. Medical confidentiality also protects relatives, except in specific situations provided for by the texts.

Saying what we are taking, what we have stopped and what we do not dare to say allows the caregiver to reason with the right pieces of the puzzle. This is not a confession: it is care information.