(NewsNation) — A new study in the United Kingdom showing a connection between one man’s “blue legs” and his long COVID aims to raise awareness of the symptom.

Study authors Dr. Manoj Sivan at the University of Leeds in the United Kingdom, and Nafi Iftekhar, a medical student, learned of the phenomenon when a 33-year-old man who developed acrocyanosis was referred to their clinic. Acrocyanosis is a venous pooling of blood in the legs, which according to the National Institutes of Health is “characterized by bluish discoloration of skin.”

The man reported his legs would progressively feel heavy, tingly, itchy and become “dusky” when he stood.

After one minute of standing, the University of Leeds said in a news release, the patient’s legs began to redden, becoming increasingly blue over time, and his veins became more prominent. This blue color became more pronounced after ten minutes.

When the patient returned to a non-standing position, though, his original color returned just two minutes later.

According to the patient, these discoloration symptoms started after he was infected with COVID-19. He had also been diagnosed with postural orthostatic tachycardia syndrome, or POTS, after getting COVID.

“This was a striking case of acrocyanosis in a patient who had not experienced it before his COVID-19 infection,” Sivan said in a statement. Clinicians may not be aware of the link between acrocyanosis and Long COVID, Sivan went on.

In addition to the blue legs, the patient had also reported “muscular pain, sleep disturbance, visual difficulties, sexual dysfunction and brain fog” after his COVID diagnosis.

Long COVID, the University of Leeds wrote, affects many systems in the body and can have an array of symptoms, affecting people’s ability to perform daily activities. Those who have long COVID might find it affects their autonomic nervous system, which is responsible for regulating blood pressure and heart rate. 

“We need to ensure that there is more awareness of dysautonomia in long COVID so that clinicians have the tools they need to manage patients appropriately,” Sivan said.

Between 10% and 30% of people are estimated to have experienced some form of long COVID after recovering from a coronavirus infection.

The National Institutes of Health began a handful of studies to test possible treatments for long COVID this summer as part of its $1.15 billion RECOVER project.

Recently, hospitals have seen an increased number of people with serious complications from COVID. Last week, the Associated Press wrote that coronavirus hospital admissions have inched upward in the United States since early July.

The Associated Press contributed to this report.