Symptoms can appear within minutes or days and require immediate attention. Changes in the skin, pupils and breathing are among the main indicators.
The signs can be subtle: a persistent headache , sudden malaise, dizziness . At first glance, these are common symptoms. However, in certain cases, the body is giving signs of something more serious, such as possible poisoning or intoxication. The challenge is to know how to recognize the warning and seek medical attention quickly, before the condition worsens.
“The difference between medicine and poison is in the dose.” This phrase, attributed to the 16th-century physician and philosopher Paracelsus, is still used today as a starting point for understanding the severity of poisoning. This idea is reinforced by Dr. Paulo Correia, the emergency room coordinator at Hospital Brasília, part of Rede Américas.
According to him, seemingly harmless substances, such as painkillers, antipyretics and even cough syrups, can become dangerous agents if ingested in large quantities. “Even medications that are commonly used daily, and usually undervalued by the population, can cause serious poisoning when accidentally ingested in high doses,” he warns.
Main warning signs
Each substance causes a specific combination of clinical signs (called toxidrome), but some symptoms are recurrent in practically all situations. “ Diarrhea , nausea and vomiting, dizziness or fainting, mental confusion, agitation or drowsiness, headache, difficulty breathing, fast or slow heartbeat, excessive sweating or absence of sweat, convulsions, changes in skin or lip color (bluish, pale, reddish), very small or very dilated pupils”, describes the specialist.
Dr. Marina Salgado, an infectious disease specialist at Hospital Sírio-Libanês, reinforces this list of warning signs, adding other important symptoms, such as abdominal pain, dry mouth or excessive salivation, visual changes, difficulty swallowing or speaking, and extreme drowsiness or even loss of consciousness. “These are signs that, when present, require immediate medical evaluation, especially when they appear suddenly or without apparent cause.”
Symptoms may develop immediately or late, depending on the toxic agent. “It depends on the substance and the amount ingested, inhaled or in contact with the skin. Some symptoms appear minutes after contact (such as strong cleaning products or animal poisons), while others may take hours or even days to appear (such as certain medications, pesticides or heavy metals),” explains Dr. Paulo. Therefore, he recommends that even when there are no signs immediately after exposure, the person’s general condition should be monitored with extra attention in the following hours and days.
Among the main physical signs, he highlights:
- Eyes: very small or very dilated pupils, red or yellow eyes or watery eyes;
- Skin: pale, reddish, bluish or blotchy; there may be sweating or dryness;
- Mouth: excessive salivation, metallic taste, sores or burning;
- Breathing: breath with a different odor, rapid, slow or irregular breathing;
- Movements: tremors, convulsions, drowsiness and disorientation.
“Any of these signs are a cause for serious concern and should prompt immediate emergency care,” the doctor emphasizes.
Differences between food poisoning and poisoning
Another point of attention is the distinction between common food poisoning and poisoning, which is not always easy. Food poisoning usually has bacterial or viral causes, and its impact is concentrated in the gastrointestinal tract.
“Common food poisoning usually occurs after ingesting food contaminated by bacteria or toxins (such as spoiled mayonnaise or poorly preserved seafood), which can lead to significant irritation of the gastrointestinal tract and, usually, nausea, vomiting, abdominal pain and diarrhea, with the onset of symptoms usually occurring within 24 hours after ingesting contaminated food,” says Dr. Paulo.
Despite the discomfort and intensity of the symptoms, these conditions generally do not involve the nervous, cardiovascular or respiratory systems. “Although these can be intense and potentially incapacitating symptoms, they rarely lead to neurological, respiratory or cardiac symptoms,” he explains. However, in cases of poisoning by chemical products or medications, these symptoms are often present. When signs such as mental confusion, irregular heartbeat, difficulty breathing or changes in skin color appear, it is important to be alert.
According to Dr. Marina, the distinction can be made by observing the time of onset of symptoms and the context. “Poisonings tend to have a more sudden onset and more severe manifestations. Food poisoning, on the other hand, usually affects several people who ate the same food and involves symptoms that are more limited to the digestive system,” she explains. Asking if other people have become ill, checking for a history of exposure to suspicious chemicals or environments, and observing signs such as burns, altered pupils or unusual odor in the breath are important measures in the initial evaluation.
When in doubt, the specialist’s recommendation is clear: don’t take any risks. “When in doubt, especially when faced with severe symptoms or atypical signs that do not only affect the digestive system, always seek immediate medical attention.”
More than identifying the exact cause, early care can save lives, especially in the case of children, the elderly or people with pre-existing illnesses, who have less physiological reserve to deal with the impact of toxic substances on the body.