Pneumonia: Signs and Symptoms

Medically Reviewed by Poonam Sachdev on April 08, 2024
Written by WebMD Editorial Contributors
4 min read

Pneumonia, a lung infection, can cause coughing, hacking, or wheezing. You might think it’s just a cold or the flu. How can you tell the difference? Your other symptoms can give you some clues.

Pneumonia symptoms can range from mild to serious, depending on what’s causing the illness and how healthy you are in general. They can include:

  • High fever, up to 105 F
  • Coughing up greenish, yellow, or bloody mucus
  • Chills that make you shake
  • Feeling like you can’t catch your breath, especially when you move around a lot
  • Feeling very tired
  • Loss of appetite
  • Sharp or stabbing chest pain (you might feel it more when you cough or take a deep breath)
  • Sweating a lot
  • Fast breathing and heartbeat
  • Lips and fingernails turning blue
  • Confusion (in older people)

Bacteria and viruses are the most common causes of pneumonia. Fungi and parasites can sometimes cause it.

Bacterial pneumonia symptoms

When bacteria are the cause, the illness can come on either slowly or quickly. It tends to be more serious than other types. You may have a high fever, sweat a lot, breathe faster, and have a faster pulse. Your lips and nailbeds could also turn a bluish color from a loss of oxygen in your blood, and you may feel confused or delirious.

Viral pneumonia symptoms

When a virus causes pneumonia, you’re more likely to notice symptoms over several days. Early signs, such as fever, dry cough, headache, and weakness, will look like the flu but get worse in a day or two. You'll cough more and have shortness of breath and muscle pain. You could also have a high fever and blue lips.

Walking pneumonia symptoms in adults

This is an informal name for a type of pneumonia caused by Mycoplasma pneumoniae, a type of bacteria. Compared to other types of pneumonia, you'll probably have milder symptoms and won't need bed rest.

When kids have pneumonia, their symptoms might be harder to spot. They may have:

Symptoms of pneumonia in babies

Symptoms of pneumonia in babies might be vague, like: 

  • Fussiness
  • Trouble feeding
  • Noisy breathing or a grunting sound when they breathe
  • Peeing less often or diapers that are drier than normal
  • Pale skin
  • Limpness

It’s tricky because pneumonia can be a complication of colds and flu. This happens when the germs that cause those common illnesses get into your lungs. You might be feeling better, but then you start getting symptoms again -- and this time, they can be a lot worse.

Cold symptoms tend to start slowly. You’re more likely to sneeze and have a runny nose and sore throat than with either the flu or pneumonia. Colds don’t usually cause a fever in adults.

The top clue that you have the flu is that the symptoms come on strong, seemingly out of nowhere. You may have:

  • Fever above 100.4 F
  • Headache
  • Severe aches and pains
  • Extreme tiredness
  • Dry, hacking cough

These symptoms tend to ease up in 2 to 5 days, but you might have a mild cough or sore throat for 2 weeks.

After starting treatment for pneumonia, a cough and fatigue can stick with you for several weeks. You could also have ongoing health problems, such as:

  • Trouble exercising
  • Cardiovascular disease that gets worse
  • Diminished quality of life
  • A higher chance of chronic lung disease in children

How long does pneumonia last?

You should start to feel better within a couple of days after starting pneumonia treatment, depending on:

  • Your age
  • What caused your pneumonia
  • How serious your pneumonia is
  • If you have other health conditions or problems

Call your doctor right away if you or your child has a cold or the flu that doesn’t get better with rest and treatment, if the symptoms start to get worse, if you have other medical problems or a weakened immune system, or if you notice possible symptoms of pneumonia. Anyone with this lung infection needs medical attention.

Some signs of pneumonia, an infection in your lungs, include a high fever, coughing up colored mucus, feeling very tired, and having trouble breathing. Bacteria, viruses, fungi, and parasites can cause pneumonia, and the symptoms may differ depending on the cause. In children, symptoms of pneumonia might include fast breathing, coughing, and having bluish skin or lips.

How long can you have pneumonia without knowing?

If you have walking pneumonia, symptoms can take 2 to 4 weeks to appear. With other types, symptoms can ramp up gradually or suddenly; you could also have symptoms so mild that you hardly notice them.

Can you have pneumonia without a cough?

Although a cough is a common symptom of pneumonia, it's possible you won't have one.