Your Health Questions
Answered by Professionals

There are several factors to consider—“long COVID” generally means new or ongoing symptoms (often fatigue, breathlessness, or brain fog) that last beyond 4–12 weeks after a COVID-19 infection and may flare with physical or mental effort. To know if this applies to you, check the timing, pattern, and impact on daily life, and have a clinician rule out other causes with basic labs and heart/lung evaluations (seek urgent care for severe chest pain, sudden shortness of breath, fainting, or signs of a blood clot). See below for a complete checklist, specific tests, self-care and rehab strategies, and red flags that can guide your next steps.

Yes—older adults can experience Tylenol side effects differently because age-related liver/kidney changes, other health conditions, and multiple medications increase the risks of liver injury, interactions, and sensitivity (like dizziness or confusion). There are several factors to consider, including a lower recommended daily maximum (≤3,000 mg) and higher risks with liver/kidney disease or alcohol use—see the complete guidance and key warning signs below.

Cats can catch SARS‑CoV‑2 (usually from their owners) and most have mild or no symptoms; importantly, there are no confirmed cases of cats transmitting COVID to people, and CDC/WHO consider the risk low. There are several factors and precautions to consider if someone in your home is sick—see below for details on reducing risk, what symptoms in cats to watch for, and when to contact a vet or doctor.

Yes—an underactive thyroid (hypothyroidism) can lower alkaline phosphatase by slowing bone turnover, and levels often normalize after thyroid hormone treatment. There are several other potential causes (nutritional deficiencies, malabsorption, rare genetic disorders), so persistent low results merit repeat testing and checks like TSH/free T4 and nutrient levels—see the important details and next‑step guidance below.

Yes—workouts can trigger pain under the right armpit in females, most often from muscle strain (pectoralis/serratus/latissimus), pectoralis minor syndrome, or improper form and overuse. There are several factors to consider: other causes include swollen lymph nodes, breast or skin conditions, intercostal or cervical nerve issues, and thoracic outlet problems, with red flags like a hard lump, fever, numbness, or sudden severe pain needing prompt care. See below for how to tell if it’s workout-related, prevention steps, and guidance on when to see a clinician.

Yes—swollen axillary lymph nodes can cause pain under the right armpit in women, often tender and worse with arm movement, and most commonly linked to infections, recent vaccinations, or minor injuries. Seek prompt care if a lump is hard, fixed, rapidly enlarging, >2 cm, or accompanied by fever, night sweats, weight loss, or breast changes; imaging like ultrasound and mammography may be used. There are several factors to consider; see below for other possible causes, home assessment tips, supportive care, and when in-person evaluation or biopsy may be needed.

Current evidence shows COVID-19 vaccines do not cause infertility in men or women—large studies (including IVF), global pregnancy registries, and major medical organizations (ACOG, ASRM, WHO) all support their safety for fertility and pregnancy. If you’re trying to conceive or undergoing treatment, there’s no need to delay vaccination; infection itself poses more risk to reproductive health—there are several factors to consider, so see the details below for how this may affect your next steps and when to contact a clinician.

New COVID strains mainly differ in how easily they spread, how well they dodge parts of our immune defenses, and (to a lesser extent) how severe illness may be. Vaccines and boosters still provide strong protection against severe disease, so aim for informed vigilance rather than alarm, especially by updating shots and using layered precautions in higher-risk settings. There are several factors to consider—like your personal risks, local spread, and when to test or seek care—so see below for important details that could shape your next steps.

For sudden testicle pain when torsion is a concern, treat it as an emergency—go to the ER now; while you head there or wait, elevate/support the scrotum, apply a cold pack 10–15 minutes at a time, rest on your back with knees bent, and consider ibuprofen as directed if safe (avoid warm baths until torsion is ruled out). Red flags include sudden severe one‑sided pain, rapid swelling/redness, a high‑riding testicle, and nausea/vomiting—torsion needs treatment within about 6 hours to prevent permanent damage. There are several factors to consider; see below for step‑by‑step pain relief, what not to do, and the exact urgent steps and evaluation to expect.

Left arm pain can be a heart attack warning—especially if it comes with chest pressure, shortness of breath, sweating, nausea/lightheadedness, or pain spreading to the jaw, back, or right arm; in those cases, call emergency services immediately. On its own, left arm pain is often from muscle, joint, or nerve issues, but there are several factors to consider; see below for how to tell heart-related symptoms from more common causes and the exact next steps. If the pain is sudden or severe, or you have heart risk factors, seek prompt medical care even without chest pain.

Yes—tonsillitis in adults is contagious: viral infections typically spread from a day before symptoms through about 5–7 days (longer with mono), while strep (bacterial) remains contagious until 24 hours after starting the right antibiotic and can last much longer without treatment. It’s generally safe to return to work when you’re fever-free for 24 hours and symptoms are improving; for confirmed strep, wait at least 24 hours after the first antibiotic dose. There are several factors to consider (testing, symptom severity, workplace precautions)—see below for important details that could change your next steps.

You generally can’t make a stye disappear overnight, but you can quickly reduce pain and swelling with frequent warm compresses (10–15 minutes, 3–5 times/day), gentle lid hygiene, stopping makeup/contacts, and, when appropriate, an antibiotic ointment or prescription azithromycin 1% eye drops—never squeeze it. Most clear in 7–10 days; seek care sooner for worsening redness/swelling, vision changes, or fever. There are several factors and options (including when to use oral antibiotics or drainage) that could change your next steps—see the complete guidance below.

Lower left abdominal pain in women can stem from the GI tract (diverticulitis, IBS/IBD, constipation, colitis or obstruction), gynecologic causes (ovarian cysts or torsion, ectopic pregnancy, endometriosis, PID, ovulation pain), urinary issues (UTI, kidney stones, pyelonephritis), or musculoskeletal/hernia and vascular problems. There are several factors to consider—and some are emergencies, especially sudden severe pain, fever, vomiting, abnormal vaginal bleeding, or symptoms in early pregnancy—so see the complete details below to recognize red flags and choose the right next steps.

In women, pain under the right armpit can stem from muscle strain; swollen lymph nodes or skin infections (including abscesses or shingles); breast issues like mastitis or, less commonly, cancer; nerve problems; referred pain from the gallbladder or liver; or even a vein clot. There are several factors to consider—see below for specifics, urgent warning signs (severe chest pain or breathing trouble, fever with redness, arm swelling/discoloration, rapidly growing lumps with night sweats/weight loss), and next steps including self-care for mild strain versus seeing a clinician if symptoms persist beyond 1–2 weeks or worsen.

The “razor threat” COVID variant isn’t an official WHO designation but a media nickname for spike mutations; early lab data suggests modest immune escape, with no real-world evidence it’s more severe in children. Parents shouldn’t panic—keep up vaccination/boosters, masking in crowded indoor spaces, good ventilation and hand hygiene, and test promptly while watching for red-flag symptoms, especially in kids with chronic conditions. There are several factors to consider that could change your next steps (when to test, isolate, or seek urgent care); see below for important details and tools.

Usually benign, but left eyelid twitching in women is more concerning if it lasts longer than two weeks, spreads to other facial muscles or forces the eye closed, follows head/eye injury, or occurs with neurological or systemic symptoms (facial weakness, vision or speech changes, numbness, fever, unexplained weight loss). These can point to blepharospasm/hemifacial spasm, thyroid eye disease, electrolyte issues, or neurological disorders (including stroke)—there are several factors to consider; see the complete details and recommended next steps below.

Red-flag Tylenol side effects that may signal liver trouble include jaundice (yellow skin/eyes), dark urine, pale stools, right‑upper abdominal pain, persistent nausea/vomiting, extreme fatigue/weakness, loss of appetite, or confusion. If you notice any of these—especially jaundice, dark urine, or severe abdominal pain—stop Tylenol and seek urgent care; there are several important risk factors, safe‑dose limits, and next steps to consider—see details below.

There are several factors to consider. Even when not pregnant, post‑workout nipple pain is usually from friction/chafing, sweat/salt irritation, contact dermatitis, yeast/bacterial overgrowth, chest‑muscle strain, or normal hormone sensitivity—and it often improves with a well‑fitting moisture‑wicking sports bra, protective balm, and prompt drying. See below for step‑by‑step prevention and the red flags (new lump, discharge, spreading redness/fever, or skin changes) that determine when to seek medical care.

Skin irritation is a leading cause—often from contact dermatitis (soaps/detergents, fabrics), eczema/psoriasis, chafing, or allergies—but hormones, infections (bacterial/yeast/herpes), injury, and rare conditions like Paget’s disease or inflammatory breast cancer can also contribute. Try gentle, fragrance-free products, a supportive bra, cool compresses, and short-term hydrocortisone for dermatitis, and seek care urgently for persistent/worsening pain, discharge (especially bloody), new lumps, spreading redness/fever, or nipple/skin changes. There are several factors to consider; key details and next steps that could affect your care are outlined below.

There are several factors to consider: sudden right‑side armpit pain is often from muscle strain, swollen lymph nodes, or skin issues, but can also arise from shingles or nerve irritation, or be referred from deeper conditions like gallbladder disease, liver/diaphragm irritation, atypical heart symptoms, or (rarely) a lung apex tumor. Seek urgent care for severe or unexplained pain, fever/redness or pus, a hard or rapidly enlarging lump, chest tightness/shortness of breath or sweating, jaundice, or new arm weakness/numbness. See below for key details that can guide your next steps, including what to watch for, home care, prevention, and when to call a doctor.

Stop activity, lie down, support the scrotum with a jockstrap or snug briefs, apply an ice pack wrapped in a towel for 10–15 minutes on/off, elevate with a rolled towel, and use ibuprofen or acetaminophen as directed—these bring the fastest relief. There are several factors to consider, including when to add warm baths and gentle stretches and urgent red flags (sudden severe or persistent pain, swelling/redness, fever, nausea/vomiting, blood in urine/semen) that could signal torsion, infection, or hernia; see the full step-by-step guidance and when to seek care below.

As of late 2025, there is no universal U.S. COVID vaccine mandate, but targeted requirements remain—most notably the federal CMS rule for staff at Medicare/Medicaid-participating hospitals, nursing homes, home health, and other long-term care facilities. Some states and cities (especially for health and long‑term care), certain colleges, and many private employers still require vaccination; domestic travel has no mandate, while international entry rules vary by country. There are several factors to consider depending on where you work, study, or travel—see the complete details below.

Yes—free COVID-19 tests are still available: you can order at-home kits from covidtests.gov, get tests covered by most insurance and Medicare, and find no-cost testing at community clinics, Test-to-Treat sites, and some workplaces/schools. There are several factors to consider (eligibility, quantity limits, reimbursement steps, uninsured options, and when to re-test or seek treatment)—see the complete guidance below to choose the right next step.

Yes—side effects can happen after just one dose: mild nausea or headache are possible, and rarely allergic reactions like rash, facial/throat swelling, or trouble breathing may occur within hours; serious liver injury is uncommon at recommended doses and usually follows overdose, but risk is higher with liver disease, heavy alcohol use, fasting, certain medications, or age extremes. There are several factors and red‑flag symptoms to consider, including dosing limits and when to seek urgent care—see the complete details below.

Yes—most left eyelid twitching in women is benign and commonly linked to stress or lack of sleep. Other fixable triggers include eye strain from screens, caffeine or other stimulants, dry eyes/allergies, and occasionally low magnesium or potassium. There are several factors to consider—see below for simple self-care steps and the red flags (lasting >1–2 weeks, spreading to other facial muscles, vision changes, redness/swelling/discharge, after head injury, or with headaches/weakness) that mean you should seek medical care.

There are several factors to consider: COVID-19 rashes can appear as measles-like red spots, hives, small blisters, chilblain-like “COVID toes,” or lace-like discoloration, often just before, during, or shortly after other symptoms (fever, cough, loss of smell); clues include toe/finger lesions without cold exposure, intense itch, painful vesicles, and rashes lasting 1–3 weeks. If you suspect this, note other symptoms, use a symptom checker, get tested and isolate, and seek urgent care for red flags like trouble breathing, chest pain, or widespread blistering—key differentiators from allergies/drug reactions and practical treatment/next steps are detailed below.

For fast relief right now: stop activity, lie down with knees bent, support the scrotum (jockstrap or towel), apply a cold pack wrapped in cloth for 10–15 minutes at a time with breaks, and take OTC pain relievers (ibuprofen/naproxen or acetaminophen) as directed. There are several factors to consider—red flags like severe or worsening pain/swelling, nausea/vomiting, fever, blood in urine, or dizziness need urgent care—and follow-up and prevention steps can affect your next move; see below for complete details.

Yes—tonsillitis is contagious: viral cases start 1–2 days before symptoms and remain contagious while symptoms last (usually 5–7 days, sometimes a bit longer), and bacterial (strep) cases are contagious from symptom onset until about 24 hours after starting the right antibiotics—otherwise up to 2–3 weeks. There are several factors to consider that can affect return to school, how to reduce spread, and when to seek care; see the complete guidance below.

Yes—lower left abdominal pain can sometimes involve the ovary (torsion, cysts, endometriosis, infection), but it’s often due to non-ovarian problems like diverticulitis, IBS/constipation, UTIs or kidney stones, hernias, or ectopic pregnancy. There are several factors and urgent red flags to consider (e.g., sudden severe pain, fever, persistent vomiting, fainting); see the complete details below for the full list of causes, tests, and the right next steps, including when to seek emergency care.

Yes—baking soda can neutralize stomach acid and provide quick, short-term relief for occasional heartburn, aligning with guidelines that permit antacids for mild, infrequent symptoms. However, it’s not a long-term fix and carries important risks (very high sodium, gas/bloating, drug interactions, and rare alkalosis), and frequent reliance may mask GERD—there are several factors to consider; see the safe dosing tips, better OTC options, lifestyle changes, and red‑flag symptoms to act on below. If your symptoms occur more than twice weekly or are severe, seek medical evaluation.