Queen Margrethe was admitted to Rigshospitalet on Thursday afternoon due to angina pectoris.
She will be admitted over the weekend for observation and further tests.
This was stated by the Royal House in a brief press release on Thursday afternoon.
The 86-year-old Queen is tired, but in good spirits, according to the Royal House, which will announce when there is news.
A heart attack is also called angina pectoris. The condition is mainly caused by calcification in the coronary arteries of the heart, according to the website sundhed.dk.
The symptoms are often chest pain during physical exertion.
The risk of developing atherosclerosis increases if you smoke, have high blood pressure, high cholesterol or diabetes, according to sundhed.dk.
Queen Margrethe was last hospitalized in May 2025. At that time, she was hospitalized for observation due to a cold.
This was done "for safety reasons", the royal house said at the time.
/ritzau/