Strip off to seek signs of a health problem
While you may be feeling completely fine on the outside and can't spot any signs to tell you otherwise, there may be some underlying signals that something's wrong - under your clothes.
It requires a lot of courage to stand in front of a mirror naked and look at yourself, but it may be the only way you're able to discover some hidden problems.
Experts have spoken to Daily Mail Online on a few issues to keep an eye out for, and what they mean.
Dark skin in armpits
It isn't just hair removal that can leave your skin off-colour - dark, thick patches, known as acanthosis nigricans, could be a sign of early type 2 diabetes. This disorder is characterised by high blood sugar, lack of insulin and insulin resistance. The patches may also be dry and have a rough feel to them, as well as itching.
"They are linked to obesity, which in turn can cause insulin resistance, a precursor to diabetes when the body is unable to properly use the hormone insulin to regulate blood sugar levels and so the pancreas tries to produce more and more," Dr Nida Chammas, a consultant diabetes endocrinologist at the BMI Clementine Churchill Hospital, Middlesex, said. "High levels of insulin in the blood are thought to cause changes in skin cells that lead to the formation of these patches."
They're typically found in areas like the armpits, neck and groin - anywhere where skin folds.
One shoulder higher than the other
If your shoulders are uneven, or one blade is more prominent in the other when you turn to look at your back in the mirror, this could be a curving of the spine, known as scoliosis.
"Traditionally people think of scoliosis as creating an S-shape in the spine," Tony Kochhar, a consultant orthopaedic surgeon at the London Bridge Hospital, noted. "But the condition can also affect the ribs, twisting them and pushing them upwards and outwards which can throw the alignment of the shoulders."Or, it could even be the result of neurological disease multiple sclerosis, which can lead to muscle wastage.
"MS affects the messages sent by the brain to the muscles," Professor Kochhar added. "If these don’t get through, it can affect the function of the muscles, which start wasting away, so throwing the alignment of the shoulder."
Prominent veins in your neck
Your heart may not be pumping enough blood around the body at the right pressure, causing heart failure. Thick veins are a sign, as is feeling short of breathe and swollen ankles and feet, also a result of blood not being transported properly.
"This impacts on the veins carrying blood from the head to the heart," Dr Glyn Thomas, a consultant cardiologist at the Bristol Heart Institute, explained. "If there is less force to push it through then blood builds up, causing the veins to bulge."