Glossary — H

Heart failure is a chronic condition in which the heart muscle is weakened or stiffened and cannot pump blood as effectively as the body requires. Despite the alarming name, it does not mean the heart has stopped — it means the heart is struggling to keep up with demand, leading to symptoms such as fatigue, shortness of breath, and fluid buildup in the legs and lungs.

HER2 is a protein receptor found on the surface of cells that promotes cell growth and division. In approximately 15 to 20 percent of breast cancers, the gene that codes for HER2 is amplified — producing abnormally high levels of the protein — which drives aggressive tumor growth. HER2-positive breast cancer is distinct from hormone receptor–positive cancer but is increasingly treatable with targeted therapies.

A hormone receptor is a protein found inside or on the surface of a cell that recognizes and binds a specific hormone, translating that chemical signal into changes in cell behavior. In breast cancer, the presence or absence of estrogen receptors (ER) and progesterone receptors (PR) is a critical diagnostic finding that shapes treatment decisions and prognosis.

Hormone replacement therapy (HRT) uses medications containing estrogen, progesterone, or both to relieve symptoms caused by the natural drop in hormone levels during perimenopause and menopause. It can reduce hot flashes, improve sleep, and protect bone density, though it also carries risks that vary by individual health history.

HPV, or human papillomavirus, is a large family of viruses transmitted through skin-to-skin contact, most often during sexual activity. Most HPV infections clear on their own, but certain high-risk strains can cause cervical cancer, as well as cancers of the vagina, vulva, anus, throat, and penis. Vaccination and regular Pap and HPV testing are the most effective tools for prevention and early detection.

Hypertension means that the force of blood pushing against your artery walls is consistently too high. It rarely causes symptoms on its own, which is why it is called the 'silent killer,' but over years it damages blood vessels, increases the risk of heart attack and stroke, and can affect kidney function. Lifestyle changes and medication can control it effectively.

A hysterectomy is a surgical procedure that removes the uterus. It may be performed to treat conditions such as uterine fibroids, endometriosis, uterine prolapse, chronic pelvic pain, or uterine, cervical, or ovarian cancer. Depending on the reason for surgery, the procedure may also involve removing the cervix, fallopian tubes, and/or ovaries.