Sometimes you’ll start to feel better—only to rebound and get much worse. There are some emergency signs that require immediate medical care. Flu-like symptoms that seem to improve but return with a worse fever and cough is one of them, he says. You might have a “secondary infection,” which could be anything from bronchitis to pneumonia. Whatever it is, you should have your doctor take a look.
Your snot is colourful
It’s common to have thickened saliva in a cold, but if your phlegm is a strange color, then something weird is going on in your body. It’s white blood cells trying to fight infection. So if you see colors like yellow, brown, green, or even blood, then that’s concerning.
Your cold has lasted more than 3 weeks
Even though three weeks sounds like a long time, it’s highly normal for a cold to last up to 21 days. It is cough that lasts more than three weeks that tend to be concerning. These prolonged symptoms could be signs of asthma, pneumonia, or a different type of lung pathology. And over the course of those three weeks, you want to see your symptoms not only remaining stable but improving.
Your eyes are watery or itchy
If you’re tearing up nonstop—and there isn’t an adorable puppy in sight—then there’s a chance you could have allergies rather than a common cold. Sometimes it can be hard to tell the difference. There are more than a hundred strains of cold viruses. Each tends to become widespread at certain times of the year, which is why you may mistake a cold for a seasonal allergy. Other signs of allergic reactions can include hives, tongue swelling, feeling lightheaded, stomach cramps, and more.
Your cold is making you lose weight
If you’re not eating, it’s one thing, but if you’re actively losing weight while eating that could be concerning. Unexplained weight loss paired with cold-like symptoms could be a sign of hyperthyroidism, a malignancy (aka cancer), a bacterial infection, or even HIV.