Removing an alcohol group from an organic molecule means taking a hydroxyl (-OH) group off a carbon atom and replacing it with something else, usually hydrogen. The most common way to do this is through a process called deoxygenation, and the classic laboratory method is a two-step sequence that converts the alcohol into a better … Read more

Yes, you can get shingles if you had chickenpox. In fact, you can only get shingles if you have had chickenpox before. The varicella-zoster virus causes both illnesses. After you recover from chickenpox, the virus does not leave your body. It stays dormant in your nerve tissue. Years later, the virus can reactivate and cause … Read more

Waking up with a dry, sticky mouth is a common and uncomfortable way to start the day. It happens because your body naturally slows down saliva production while you sleep, but certain habits, medications, and health conditions can make it much worse. The medical term for this is xerostomia, and while it is often harmless, … Read more

When couples struggle with fertility, diet is one of the first places they look for answers. The question of what fruits increase sperm count and motility has a straightforward answer: fruits rich in antioxidants, particularly vitamin C, zinc, and folate, support the cellular health of sperm. Studies show that oxidative stress damages sperm DNA and … Read more

Elbow crutches, also called forearm crutches, are a common mobility aid after an injury, surgery, or for long-term conditions. Using them incorrectly can cause falls, nerve damage, or shoulder pain. The safe method is to keep your weight on your hands, not your armpits or wrists, and to move the crutch and opposite leg together … Read more

Your self image is the mental picture you hold of yourself. It is not just what you see in the mirror. It includes how you believe others see you, what you think you are capable of, and the story you tell yourself about who you are. This internal picture does not stay in your head. … Read more

A hard or soft lump on your forehead is usually not an emergency. Most forehead knots are benign growths like cysts, lipomas, or bone growths. Some are caused by injury. A small number need medical attention, especially if they grow quickly, change color, or cause pain. Here is what you need to know to figure … Read more

China’s air quality is a complex story of severe pollution followed by measurable, documented improvement. Over the past decade, levels of PM2.5 — the tiny particles that pose the greatest health risk — have fallen significantly in major cities, largely due to government policy. However, the air is still far from clean by international standards, … Read more

That sudden wave of lightheadedness, the tunnel vision, the ringing in your ears, and the feeling that the floor is tilting — it is alarming. You are not necessarily sick. Most of the time, this feeling is a drop in blood pressure or a temporary change in blood flow to the brain. Your body briefly … Read more