Supraventricular tachycardia is a condition in which the heart beats much faster than normal due to abnormal electrical signals in the upper chambers of the heart, known as the atria. In this condition, the heart rate may suddenly increase to 150 to 250 beats per minute, even when a person is at rest. Episodes of supraventricular tachycardia usually begin and …

Sunburn is a skin condition caused by excessive exposure to ultraviolet (UV) radiation from the sun or artificial sources such as tanning beds. When the skin receives more UV radiation than it can tolerate, it becomes inflamed and damaged, leading to redness, pain, and irritation. Sunburn usually affects areas of skin that are directly exposed to sunlight, such as the …

Sun allergy is a term used to describe a group of conditions in which the skin reacts abnormally to sunlight. When the skin is exposed to ultraviolet (UV) rays from the sun, it may develop redness, itching, rashes, or small bumps. These reactions usually occur on areas of the skin that are exposed to sunlight, such as the face, neck, …

Suicide is the act of intentionally ending one’s own life. Suicidal thoughts, also called suicidal ideation, refer to thinking about, considering, or planning suicide. These thoughts can range from brief considerations to detailed plans and may occur during periods of severe emotional distress. Suicide and suicidal thoughts are often linked to mental health conditions such as depression, anxiety disorders, and …

Subarachnoid hemorrhage is a serious medical condition in which bleeding occurs in the space between the brain and the thin tissues that cover it, known as the subarachnoid space. This bleeding increases pressure on the brain and can damage brain cells. Subarachnoid hemorrhage is most commonly caused by the rupture of a brain aneurysm, but it can also result from …

Stretch marks, also known as striae, are streaks or lines that appear on the skin when it stretches or shrinks rapidly. They commonly develop during pregnancy, rapid weight gain or loss, puberty, or intense muscle building. Stretch marks occur when the skin’s elastic fibers are stretched beyond their limit, leading to visible scars. They are usually harmless but can cause …

Stress incontinence is a type of urinary incontinence characterized by the involuntary leakage of urine during physical activities that increase pressure on the bladder. This can occur during coughing, sneezing, laughing, exercising, or lifting heavy objects. Stress incontinence is more common in women, especially after pregnancy or menopause, but it can also affect men, particularly after prostate surgery. It is …

Strep throat is a bacterial infection of the throat and tonsils caused by Streptococcus pyogenes, also known as group A streptococcus. It is highly contagious and spreads through respiratory droplets from coughing or sneezing, or by touching contaminated surfaces. Strep throat is more common in children and adolescents but can affect people of all ages. Prompt diagnosis and treatment are …

Sexually transmitted diseases are infections that are primarily spread through sexual contact, including vaginal, anal, and oral sex. They are caused by bacteria, viruses, or parasites and can affect anyone who is sexually active. Some sexually transmitted diseases cause noticeable symptoms, while others may remain silent for long periods, increasing the risk of complications and further transmission. Early testing, diagnosis, …

Staph infections are caused by Staphylococcus bacteria, commonly found on the skin or in the nose of healthy individuals. While these bacteria often cause no harm, they can lead to infection if they enter the body through a cut, wound, or medical device. Staph infections range from mild skin problems to serious, life-threatening conditions if the bacteria spread to deeper …