A uncommon side effect of lung cancer causes patients’ legs to turn blue every time they stand up.

Doctors in the UK sounded the alarm after meeting a 33-year-old Covid survivor who, after standing for just a minute, noticed his legs started turning red and turning a bluish tinge and his veins becoming more pronounced.

The condition, known as acrocyanosis, is not considered a possible by-product of overcoming a Covid infection, but University of Leeds doctors who treated the patient said it deserves more research.

It would add to an ever-expanding list of ailments believed to be linked to long-term Covid, a constellation of lingering health problems lasting weeks or even longer after overcoming the infection.

The patient, 33, presented to doctors 18 months after recovering from Covid. They diagnosed him with a condition that causes the autonomic nervous system, which controls involuntary bodily functions, to become disrupted as a result of the infection

Dr. Manoj Sivan from the University of Leeds, who treated the patient, explained that after about 10 minutes of standing, the bluish tone in the patient’s legs was much more ‘pronounced’. But the color returned to normal when he sat down again.

The discoloration is caused by a condition called acrocyanosis, which causes decreased blood flow to the extremities, leading to decreased oxygen supply in the blood.

His pulse and blood pressure were within normal ranges when he lay down, but after standing still for eight minutes, his pulse remained elevated at 127 beats per minute.

Doctors diagnosed him with postural orthostatic tachycardia syndrome (POTS), a condition that causes an abnormal increase in heart rate when standing.

The patient also reported accompanying symptoms such as a foggy and shaky feeling, as well as tingling, itching and heaviness in his legs.

Dr. Sivan said: ‘This was a striking case of acrocyanosis in a patient who had not experienced it before his Covid-19 infection.

He added that acrocyanosis has previously been seen in children with autonomic nervous system dysfunction, known as dysautonomia, a common symptom of illness that occurs after a viral infection.

“Patients experiencing this may not be aware that it could be a symptom of Lung Covid and dysautonomia and may be concerned about what they are seeing.

“Likewise, clinicians may not be aware of the link between acrocyanosis and Long Covid.”

Long Covid is still not well understood. It’s an expansive umbrella term blamed for long-term fatigue, brain fog, muscle pain, and even more symptoms. For millions of people, those symptoms have affected their daily lives.

The US government estimates that 23 million Americans have long-term Covid, defined as symptoms that persist for months after the initial infection has cleared.

About three years after the pandemic virus first emerged, the condition is still poorly understood.

Dr. Sivan added: ‘We need to ensure there is more awareness of dysautonomia in Long Covid so that clinicians have the tools they need to treat patients appropriately.’

Previous research by the team of Dr. Sivan has shown that both dysautonomia and POTS often develop in people with Long Covid.

Dysautonomia is also seen in other long-term conditions such as fibromyalgia and myalgic encephalomyelitis, also known as chronic fatigue syndrome or ME.

Dr. Sivan, Associate Clinical Professor and Honorary Adviser in Rehabilitation Medicine at Leeds’ School of Medicine, added: ‘We need more awareness about dysautonomia in long-term conditions; more effective assessment and management approaches, and further research into the syndrome.

“This will allow both patients and clinicians to better manage these conditions.”