Why pneumonia can seem like a “harmless illness”
Pneumonia is an infection that inflames the tiny air sacs (alveoli) in the lungs. Those air sacs can fill with fluid or pus, making it harder for the lungs to transfer oxygen into the blood. It can be caused by bacteria, viruses, or, less commonly, fungi.
Early pneumonia can look deceptively similar to a cold, flu, or mild respiratory infection. Some forms—sometimes called “walking pneumonia”—develop gradually and may initially leave a person feeling well enough to continue normal activities.
For adults 65 and older, pneumonia deserves particular attention because symptoms can be less typical, including confusion or an unusually low body temperature, and the illness can become serious relatively quickly.
5 early warning signs of pneumonia
1. A cough that doesn’t behave like an ordinary cold
A persistent or worsening cough is one of the most important clues.
It may initially be dry, but pneumonia can produce phlegm, sometimes yellowish, greenish, or blood-tinged. A cough that continues rather than gradually improving deserves attention, particularly when it occurs together with fever, fatigue, chest discomfort, or breathing problems.
Watch for:
- Cough becoming progressively worse.
- Increasing amounts of mucus.
- Thick or discolored phlegm.
- Blood in the mucus.
- A cough accompanied by chest pain or shortness of breath.
A cough by itself does not prove pneumonia; many respiratory infections cause coughing.
2. Shortness of breath or noticeably harder breathing
This can be a particularly important warning sign because pneumonia affects the parts of the lungs responsible for oxygen exchange.
Someone may notice that ordinary activities—walking across a room, climbing stairs, or showering—suddenly make them unusually breathless. In more serious pneumonia, breathing can become rapid or difficult even while resting.
Don’t dismiss new breathlessness as simply being “out of shape,” especially when it accompanies a respiratory illness.
Severe difficulty breathing is an emergency.
3. Fever, chills or an unusual change in body temperature
Pneumonia may cause fever, sweating and shaking chills. However, the absence of a high fever does not necessarily rule it out.
Older adults and people with weakened immune systems can sometimes develop a lower-than-normal body temperature instead of a fever.
That’s one reason pneumonia can be harder to recognize in older people: the classic “high fever and terrible cough” picture isn’t always present.
4. Unusual exhaustion or a sudden drop in energy
Profound fatigue can be an early clue.
Instead of simply feeling a little tired from a cold, a person may feel unusually weak, sleep much more than normal, lose their appetite, or struggle with everyday activities. Fatigue is a recognized pneumonia symptom and can persist even after the infection itself begins improving.
In older adults, a sudden change from their normal level of functioning can be especially significant.
5. Confusion, unusual sleepiness or a sudden change in behavior
This is particularly important in people 65 and older.
Pneumonia can cause confusion or changes in mental awareness in older adults. Someone who suddenly seems disoriented, unusually sleepy, less responsive, or noticeably different from their normal self may need medical evaluation—even if they don’t have a dramatic cough or fever.
This symptom can be overlooked because family members may initially attribute it to tiredness, dehydration, medication, or aging.
Other symptoms that can occur
Pneumonia doesn’t always present in exactly the same way. Other possible symptoms include:
- Chest pain, particularly when breathing deeply or coughing.
- Sweating and chills.
- Headache or muscle aches.
- Nausea, vomiting or diarrhea.
- Loss of appetite.
- Coughing up mucus.
- General weakness.
- Low oxygen levels.
When pneumonia becomes an emergency
Seek emergency medical care immediately for significant difficulty breathing, severe or worsening chest pain, blue/gray lips or skin, severe confusion, inability to stay awake, or rapidly worsening symptoms.
Pneumonia can interfere with oxygen delivery and, in severe cases, lead to complications requiring hospitalization or breathing assistance. Mayo Clinic notes that rapid breathing, confusion, low blood pressure, declining kidney function, or the need for respiratory support are among circumstances that may require hospitalization.
Who should be especially cautious?
The risk of serious pneumonia is higher in:
- Adults 65 and older.
- Young children, particularly those under 2.
- People with chronic lung or heart disease.
- People with weakened immune systems.
- People who smoke.
- People who have recently been hospitalized.
Age matters because the immune response and the body’s ability to compensate for impaired lung function change with aging.
How doctors determine whether it is pneumonia
Symptoms alone cannot reliably distinguish pneumonia from a cold, influenza, COVID-19, bronchitis or other respiratory illnesses.
A clinician may listen to the lungs and, depending on the situation, use:
- Chest X-ray to look for inflammation in the lungs.
- Pulse oximetry to measure blood oxygen.
- Blood tests.
- Sputum testing in selected cases.
- Additional imaging or testing when the illness is severe or isn’t improving.
Treatment depends on the cause. Bacterial pneumonia may require antibiotics, while antibiotics don’t treat viral pneumonia.
The key takeaway
The biggest mistake is assuming “it’s just a cold” because the symptoms initially seem mild. A cough that persists or worsens, new breathing difficulty, fever/chills, marked fatigue, or confusion—particularly in an older adult—should prompt medical attention.
And regarding the Diane Keaton headline: her death is a reminder that pneumonia can be serious, but it would be misleading to claim that these five signs were necessarily her warning signs. The publicly available reporting does not establis