Evidence-Based Medical Knowledge You Can Trust
Infectious diseases are illnesses caused by bacteria, viruses, fungi, or parasites, spreading through contact, food, water, or vectors.
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Quick Summary The COVID incubation period is the time between exposure to the SARS-CoV-2 virus and the start of symptoms. Most people develop symptoms within 2 to 5 days, but it can range from 2 to 14 days. Some individuals remain asymptomatic yet can still … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Quick Answer: What Is H3N2 Flu? H3N2 flu is a subtype of Influenza A virus that causes seasonal flu outbreaks and is often linked to more severe illness, especially in older adults and young children. Understanding Influenza A (H3N2) Influenza viruses are grouped into types … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Quick Summary The Influenza Symptoms Chart 2026 outlines early, moderate, and severe flu symptoms, high-risk warning signs, and when emergency care is required. Influenza is a contagious respiratory illness caused by influenza A and B viruses. According to the Centers for Disease Control and Prevention … Read more
Measles Symptoms 2026 remain clinically consistent with classic measles presentation described for decades. The disease is caused by the measles virus (genus Morbillivirus) and remains one of the most contagious viral infections worldwide. According to the Centers for Disease Control and Prevention (CDC), measles spreads through respiratory droplets and airborne transmission, and up to 90% … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Measles (rubeola) is a highly contagious viral illness caused by the measles virus. Despite widespread vaccination, outbreaks continue to occur, particularly in populations with low vaccine coverage. There is no specific antiviral cure for measles; treatment aims to support the body’s response, alleviate symptoms, prevent … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Overview of COVID‑19 Duration Acute Phase Most people infected with SARS‑CoV‑2 recover from the acute COVID‑19 illness within 4 weeks of symptom onset. Recovery timelines vary with symptom severity: Typical Timeline Breakpoints The clinical literature commonly divides the course of COVID‑19 into phases: Long COVID … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD Introduction: What This Chart Reflects This article summarizes symptoms currently associated with acute COVID‑19 infection as recognized by major public health authorities in late 2025/early 2026. Symptoms of COVID‑19 hold continuity with prior years but may shift in prevalence due to viral evolution, immunity from … Read more
Respiratory Viruses in January 2026 Flu Still High, RSV and COVID Lower — Layered Protection Tips
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Understanding the difference between COVID-19 and seasonal influenza is essential for timely diagnosis, isolation decisions, and appropriate treatment. Both are respiratory viral infections. Both can cause fever, cough, fatigue, and body aches. Yet they differ in transmission patterns, complications, testing protocols, and high-risk populations. This … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Quick Answer: Why Does Diarrhea Happen? Diarrhea is your body’s way of quickly getting rid of unwanted “guests.” It usually happens when your intestines can’t absorb enough fluid or when they secrete too much fluid, leading to loose, watery stools. The most common causes are … Read more
Medically Reviewed and Compiled by Dr. Adam N. Khan, MD. Quick Answer: Is Hepatitis Contagious? Yes, viral hepatitis is contagious, but how it spreads depends entirely on the type. Hepatitis A and E are usually spread through contaminated food or water. Hepatitis B, C, and D are spread through contact with infected blood or bodily … Read more
Chikungunya is a virus spread by mosquitoes that causes high fever and severe joint pain. In early 2026, health experts noticed a rise in cases across the Americas and parts of Asia. While a vaccine called IXCHIQ is available, new safety rules in 2026 limit its use to adults aged 18 to 59 who do … Read more
Have you ever wondered why, even as the world moves past the height of the pandemic, health experts keep urging us to get those updated shots? It’s not just routine advice—it’s rooted in evolving science that’s making a real difference in how we handle this virus. As someone who’s followed the twists and turns of … Read more
Have you ever paused amid the chaos of a global event and wondered, “How did this all really begin?” That’s the question at the heart of the COVID-19 story—a pandemic that reshaped our world in ways we’re still unpacking. As someone who’s spent years tracking infectious diseases and their impact on everyday health, I’ve seen … Read more
As we step into 2025, the world of health diagnostics continues to shift, much like the seasons that bring both renewal and uncertainty. You’ve probably found yourself staring at a box of rapid antigen tests tucked away in your medicine cabinet, wondering if those little strips are still reliable after months—or even years—of storage. Is … Read more