The typical symptoms of alcohol intolerance are generally similar to the symptoms that also occur in healthy people after the consumption of alcohol. In the case of alcohol intolerance, however, the symptoms occur even at much lower levels of ingested alcohol and can lead to life-threatening poisoning. In addition, the “hangover” symptoms last for several days, depending on the extent of the intolerance.
The symptoms include circulatory problems caused by the vasodilating effect of alcohol. To counteract this, the body reacts by increasing the heart rate, this increase is also called tachycardia. Also caused by the dilation of the blood vessels is a so-called flush symptomatology.
This means that there is redness and swelling all over the body, especially on the face. A further consequence of the dilation of blood vessels is an increased heat radiation, which is accompanied by a feeling of heat. Furthermore, even a small amount of ingested alcohol can cause headaches if the patient is intolerant to alcohol.
Other symptoms that typically occur are nausea, stomach problems and diarrhoea. The nausea is caused on the one hand by the stomach problems caused by an increased acid production in the stomach, on the other hand the nausea is caused by the persistent high concentration of the toxins ethanol and acetaldehyde. A skin rash, which occurs after the consumption of small amounts of alcohol, can occur especially when consuming histamine-containing beverages such as red wine.
A rash is a serious symptom of an allergy to certain components of the alcoholic beverage consumed and should be clarified. A real allergy to ethanol is very rare, but it could also manifest itself through a rash. The cause of an allergy to components of the alcohol consumed is different from that of an alcohol intolerance.
In case of an allergy, the body classifies the respective components as dangerous and reacts by activating the immune system. An allergy can be particularly dangerous if swelling causes breathing problems. Red spots after alcohol consumption can be a sign of alcohol intolerance in combination with other symptoms.
The red spots, which mostly appear on the face, are caused by blood vessels dilated by ethanol. However, red spots also occur in healthy people after alcohol consumption. Normally, however, only after the consumption of very large amounts of alcohol.
Diarrhoea can generally be caused by the consumption of alcohol. In the small intestine, the cells of the intestinal wall are affected by alcohol. An important function of the intestine is the absorption of water and salt.
This process is impaired by the effect of alcohol and more water remains in the stool. This leads to diarrhoea after the absorption of alcohol. In addition, a small proportion of the alcohol itself remains in the intestine, which in turn binds water and thus also has a laxative effect.
Diarrhoea can be an indication of alcohol intolerance, but this is not usually the only symptom. Diarrhoea can also have many causes. Also ingested food can lead to diarrhoea. However, if diarrhoea occurs more often after ingesting small amounts of alcohol, it is possible that an alcohol intolerance is present.