Although showers are expected in some parts of Spain in the coming days, the month of August is passing with temperatures above normal. The Aemet even predicts that it will end up being one of the three warmest on record. It is well known that Extreme heat has a huge impact on health. Although there are some pathologies that are not as widely known, such as thrombosis.
“The blood does not circulate well at all because of the heat,” he told EL ESPAÑOL. Juan Carlos Reverterpresident of the Spanish Society of Thrombosis and Haemostasis (SETH). For this expert, there are two scenarios related to heat that can cause an increase in the risk of thrombosis.
On the one hand, during seasons with excessive temperatures it is possible that some risk factors for thrombosis become worse“The risk of dehydration can be higher in the heat, which increases blood viscosity,” says Reverter, who also points to a lack of physical exercise as another added component to vascular dilation.
Another possibility for increased risk is heat stroke. In these cases, excessive coagulation increases; and in addition to thrombosis, hemorrhages also occur simultaneously. “This It is a very serious clinical manifestation although, fortunately, rare.”
Regarding the impact that heat has on thrombosis, the president of the European Society of Medical Oncology (ESMO), Andrés Cervantes, said in a recent interview what Days with temperatures above 35ºC could aggravate this pathologyas well as cardiovascular events and respiratory disease.
Reverter, for his part, believes that it cannot be stated with certainty that the danger increases from a certain value. He does understand that “It is proportional to the increase in temperatures“And as they increase, it will not only affect the most vulnerable people due to their previous pathologies, but it will affect the entire population.
Risk factors for thrombosis include the use of the contraceptive pill, tobacco use or cancer. Sitting for long periods of time in a car or on a plane can also increase the risk, which is why the term “traveler’s thrombosis” has been coined. But when it comes to heat shock, the president of SETH gives it a second thought. greater importance to advanced age.
Venous thrombosis (in which the link with heat is most documented, according to Reverter) can occur in any population group, although from the age of 60 the probability of suffering from it increases. Therefore, not only do they have higher risk of thrombosisbut they may also be more affected by the effects of heat.
Cause difficult to attribute
According to SETH, venous thrombosis is estimated to be 100% in Spain. affects 1 in 1,000 people per year. Of these, 5% to 10% die. In the world, it is the third cause of cardiovascular mortality, only behind acute myocardial infarction and stroke. “There are many cases,” laments Reverter, “but not enough has been said about it. And even less about its relationship with heat.”
The head of the Hemotherapy and Hemostasis Unit at the Hospital Clínic de Barcelona is also aware that noticing an increase in cases “on a day-to-day basis in a centre” is difficult. It is difficult to attribute a thrombosis to heat as the main cause. Even so, and although he cannot quantify it with certainty, he believes that more cases are being seen.
The doctor Juan Carlos Soutofrom the Haemostasis and Thrombosis Unit at Sant Pau Hospital, disagrees with Reverter as he has not found sufficient evidence to confirm that when temperatures rise, so do cases of thrombosis: “Heat is not a risk factor in itself,” he comments to this newspaper.
Souto illustrates the lack of solid evidence with a simple search on Pubmed, the largest database of medical studies. Cross-referencing the terms “venous thrombosis” and “heat” yields barely 250 results in the last 60 years, when the name of the pathology alone yields 100,000.
If replaced by “temperature”, the number of searches doubles compared to the previous one. Although the resulting studies They do not observe significant differences between the different periods of the year. “It may increase during heat waves. But not because of high temperatures, but because of some heat triggers,” says Souto about the aforementioned consequences of dehydration or lack of exercise.
For this reason, the recommendations of the specialists are clear: move around regularly to avoid permanently immobile limbs (a cause of thrombosis), maintain good hydration and try to reduce the temperature of the environment as much as possible.