Selena Gomez is telling it like it is.
Last week, the "Only Murders in the Building" star took to TikTok to get candid about why her hands shake.
In a video posted earlier this month, the 30-year-old shared her makeup and skincare routine with her 45 million TikTok followers. She appeared to have a slight tremor when applying product to a sponge, leading to many critical comments about her health and physicality.
The actress replied to one social media user who mocked her unsteady hands, explaining that the shake is a side effect of her autoimmune disease.
The original TikTok comment has since been deleted.
The "Lose You to Love Me" songstress was diagnosed with lupus in 2014. She has been very open about her disease, which attacks the body's tissues and organs and causes inflammation throughout the body.
"I haven't felt it since I was younger," she said. "In the morning when I wake up, I immediately start crying because it just hurts, like, everything."
Read on to learn more about the condition Gomez has called an "everyday struggle."
What is lupus?
Lupus is a chronic autoimmune disease that causes your body's immune system to attack your own tissues and organs.
"Inflammation caused by lupus can affect many different body systems, including your joints, blood cells, lungs, heart, skin and kidneys," Sandra Evans, a retired rheumatologist specializing in lupus, tells Yahoo Canada. "It can be difficult to diagnose because its symptoms often mimic other conditions."
Although the cause of lupus is unknown, Evans explains that genetics, epigenetics, infections, viruses, certain medications and environmental factors play a role.
"Further study will strengthen our understanding of the causes of lupus, which should lead to improved diagnosis, treatment and prevention," says Evans.
Who is at risk of lupus?
While anyone can get lupus, the condition usually affects women between the ages of 15 and 44.
"Approximately nine out of 10 adults with the disease are women," Evans explains. "It’s also more common in women of Hispanic, Native American, Asian and African American descent than in Caucasian women."
Research also suggests that people who have a family member with lupus or another autoimmune disease may be more at risk, but it's likely that a combination of factors trigger the condition.
What are the signs and symptoms of lupus?
No two cases of lupus are exactly alike and symptoms may differ from patient to patient, which makes the disease difficult to diagnose. Further, symptoms may develop slowly or come on suddenly, and may be or mild or severe.
"Most people living with lupus also have 'flares,' where symptoms get worse for a period of time, then improve or even disappear entirely," says Evans.
The most telling sign of lupus — a facial rash that resembles butterfly wings across both cheeks — occurs in many but not all cases. Other symptoms include join pain and stiffness, fever, fatigue, anxiety, shortness of breath, dry eyes, headaches, chest pain and skin lesions.
"No single test can diagnose lupus, and it could take months or even years to really be sure. But usually, blood and urine tests, a physical exam and skin biopsies are used to make a diagnosis," adds Evans.
If you or someone you know has any of the above symptoms, it's important to see a doctor.
How is lupus treated?
Treatment can depend on the severity of your symptoms. Once you're diagnosed, your physician will refer you to a rheumatologist who treats symptoms like joint pain and fatigue.
"Your rheumatologist will develop a personalized treatment plan that will help you prevent or treat flares, balance hormones, strengthen the immune system and reduce pain," says Evans. "You may also get referred to a dermatologist to treat skin issues or a nephrologist if your kidneys are affected."
If you have lupus, you'll likely have a range of feelings about your condition, from worry and fear to extreme frustration. The challenges of living with the disease can increase your risk of mental health problems such as stress, anxiety and low self-esteem.
To help cope, Evans suggests connecting with others who have lupus, gather support among friends and family, and make time for self-care.
How can I prevent lupus?
There is no single way to prevent lupus, but knowing what causes the disease can help you prevent certain symptoms.
"I would recommend limiting your time in direct sunlight, avoid overusing medications if possible, get enough sleep and develop stress management techniques," suggests Evans. "As with everyone, it's important to exercise regularly, drink lots of water, and eat a healthy diet to prevent viruses or infections that can lead to the development of lupus."