Symptoms of Pneumonia in Adults and Children

Pneumonia is one of the leading infectious causes of hospitalization and death in the United States, sending hundreds of thousands of people to the hospital each year, according to the Centers for Disease Control and Prevention. Yet many people initially mistake the symptoms of pneumonia for a bad cold or the flu, delaying treatment that could keep the infection from becoming dangerous. Recognizing pneumonia early — especially in high-risk groups like older adults, young children, and people with chronic conditions — can be the difference between recovering at home and ending up in the ICU. This article covers the symptoms of pneumonia in adults and children, the emergency warning signs, and how to lower your risk. Our medical conditions guide covers additional conditions and their warning signs. This is general education, not medical advice.

What Is Pneumonia?

Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs. The air sacs may fill with fluid or pus, causing cough with phlegm, fever, chills, and difficulty breathing. Multiple organisms can cause pneumonia, including bacteria, viruses, and fungi, and the likely cause shapes both the symptoms and the treatment.

Bacterial pneumonia is the most common type requiring medical treatment. Streptococcus pneumoniae (pneumococcus) is the leading bacterial cause, according to the National Library of Medicine (StatPearls). Bacterial pneumonia often develops after a cold or flu has weakened the respiratory defenses.

Viral pneumonia accounts for a large share of community-acquired pneumonia cases. Influenza, respiratory syncytial virus (RSV), SARS-CoV-2 (the virus that causes COVID-19), and other respiratory viruses can cause it. Viral pneumonia is generally milder than bacterial pneumonia but can still be severe, especially in older adults, infants, and immunocompromised patients.

Walking pneumonia (atypical pneumonia) is a milder form often caused by Mycoplasma pneumoniae. Symptoms are less severe, and patients can often continue daily activities, hence the name. It is most common in older children, teens, and adults under 40, and outbreaks can rise and fall from year to year, so ask your clinician what is circulating locally.

Common Symptoms of Pneumonia in Adults

Pneumonia symptoms can range from mild to life-threatening depending on the cause, your age, and your overall health. In otherwise healthy adults, symptoms typically develop over 1 to 3 days, often following an upper respiratory infection.

Persistent cough, often producing phlegm. The cough of pneumonia is typically productive, meaning it brings up mucus that may be green, yellow, rust-colored, or even blood-tinged. A dry, hacking cough is more common with viral and atypical pneumonia. The cough tends to worsen rather than improve over several days, which helps distinguish pneumonia from a resolving cold.

Fever, sweating, and shaking chills. Bacterial pneumonia often causes high fever with shaking chills. Viral pneumonia may produce a lower fever. Importantly, older adults may develop pneumonia without significant fever, which can delay diagnosis in this vulnerable group.

Shortness of breath. Difficulty breathing, especially with exertion, is a hallmark of pneumonia. The infected lung tissue cannot efficiently exchange oxygen and carbon dioxide. You may notice you are breathing faster than normal or feel winded climbing stairs or walking short distances. Rapid breathing at rest is a warning sign that needs prompt evaluation.

Chest pain that worsens with breathing or coughing. Sharp or stabbing chest pain, particularly on one side, that intensifies when you take a deep breath or cough is called pleuritic pain. It results from inflammation of the pleura, the membrane surrounding the lungs. According to the Mayo Clinic, pleuritic chest pain is one of the more distinctive pneumonia symptoms — though any severe or constant chest pain should be treated as an emergency until a clinician rules out a cardiac cause.

Fatigue and weakness. Pneumonia drains energy more than a typical respiratory infection. The fatigue can persist for weeks after the acute infection resolves, and many patients underestimate the recovery time needed.

Loss of appetite, nausea, and occasionally vomiting or diarrhea. Gastrointestinal symptoms are more common with certain causative organisms, particularly Legionella pneumonia, and dehydration from poor intake can itself become dangerous.

Symptoms of Pneumonia in Children

Children often present differently than adults, and younger children cannot always articulate what they are feeling, so caregivers need to watch behavior and breathing closely.

In infants and toddlers: Fast breathing is the single most reliable sign. The World Health Organization identifies fast breathing as the best clinical indicator of pneumonia in young children (as a rough guide, more than about 60 breaths per minute in a newborn, more than 50 in an infant under 12 months, and more than 40 in a child aged 1 to 5). Also look for nasal flaring, chest retractions (skin pulling in between or below the ribs with each breath), grunting sounds while breathing, bluish lips, poor feeding, and fewer wet diapers than usual (a sign of dehydration). Fever may or may not be present.

In older children: Symptoms more closely resemble adult pneumonia: cough, fever, rapid breathing, and chest pain. Some children complain primarily of abdominal pain (referred from the lower lungs) rather than chest symptoms. Wheezing may be present, particularly with viral pneumonia.

In all children: Unusual lethargy, refusal to eat or drink, and extreme irritability should raise concern. A child who is breathing hard, looks pale or bluish, is grunting, or is not responding normally needs immediate medical attention. Trust your instincts — caregivers often notice a child is “not right” before other signs are obvious.

Bacterial vs Viral Pneumonia: Symptom Differences

Distinguishing bacterial from viral pneumonia based on symptoms alone is imperfect, and only a clinician can confirm the cause, but some patterns emerge.

Bacterial pneumonia tends to cause a more abrupt onset with high fever, shaking chills, a productive cough with colored sputum, and rapid clinical decline. Patients often look and feel quite sick. A chest X-ray typically shows a dense area of consolidation in one specific part of the lung (lobar pneumonia).

Viral pneumonia more often develops gradually after a few days of cold or flu symptoms. Fever is usually lower, the cough may be dry initially, and symptoms may be spread more evenly across both lungs. Patients generally appear less acutely ill than those with bacterial pneumonia, though exceptions are common — influenza and COVID-19 pneumonia can be severe.

Atypical (walking) pneumonia comes on gradually with a persistent dry cough, low-grade fever, headache, and fatigue. Patients often feel well enough to continue daily activities, leading to delayed diagnosis. Despite the milder symptoms, a chest X-ray may show significant lung involvement.

Emergency Warning Signs

When to seek emergency care: Call 911 or go to the nearest emergency room if you or someone you are caring for experiences any of the following: severe difficulty breathing or gasping for air; breathing that is much faster than normal; bluish or grayish skin color (lips, fingertips, or face); chest pain that is severe or constant; confusion or altered mental status; inability to keep fluids down with signs of dehydration; or a very high fever that will not come down. Coughing up blood also warrants urgent evaluation.

In children, emergency signs include very fast breathing, labored breathing with visible rib retractions, grunting with each breath, flaring nostrils, bluish skin or lips, inability to drink, far fewer wet diapers, and extreme sleepiness or difficulty waking. Any infant under about 2 months with a fever should be seen urgently.

Older adults deserve special vigilance. Adults over 65 may develop pneumonia with atypical presentations: confusion or delirium, a fall, weakness, or simply “not being themselves” may be the primary sign, without the expected high fever and cough. According to NIH-indexed research, delayed diagnosis in older patients is strongly associated with worse outcomes, so a low threshold for evaluation is appropriate.

Risk Factors and Prevention

Certain groups face significantly higher pneumonia risk. Adults over 65, children under 2, people with chronic lung disease (COPD, asthma), heart disease, diabetes, liver or kidney disease, or weakened immune systems, current smokers, and people recovering from recent surgery or prolonged bed rest are all at elevated risk. If you belong to a high-risk group, treat new respiratory symptoms with fever seriously and seek same-day evaluation.

Vaccination is the most effective prevention, and the recommendations have changed in ways worth knowing for 2026:

• Pneumococcal vaccines. The CDC now recommends routine pneumococcal vaccination for all adults age 50 and older (the threshold was lowered from 65), as well as for younger adults and children with certain risk conditions. Several vaccines are in use, including the conjugate vaccines PCV15, PCV20, and PCV21 (Capvaxive), and the polysaccharide vaccine PPSV23. Which vaccine and schedule is right for you depends on your age, prior doses, and health conditions — ask your clinician or pharmacist. See the CDC’s pneumococcal vaccination guidance for current details.
• Annual flu vaccine. Influenza frequently precedes bacterial pneumonia, so a yearly flu shot lowers pneumonia risk indirectly.
• COVID-19 vaccine. Staying up to date with COVID-19 vaccination reduces the risk of severe COVID pneumonia, particularly for older and higher-risk adults; recommendations are updated periodically, so check the current guidance.
• RSV vaccine. RSV vaccines are now recommended for older adults — routinely at age 75 and older, and for adults roughly 50 to 74 who are at increased risk. RSV vaccination in pregnancy and an RSV antibody for infants also help protect babies. Confirm current age and eligibility rules with your clinician.

Beyond vaccines, good hand hygiene, not smoking, and effectively managing chronic conditions all lower risk.

Diagnosis and Treatment Overview

When pneumonia is suspected, a clinician will typically start with a physical exam (listening for crackles or diminished breath sounds) and a chest X-ray. The X-ray helps confirm pneumonia and shows the location and extent of the infection. Pulse oximetry — a painless clip on the finger — measures blood oxygen and helps gauge severity.

Additional tests may include a complete blood count (CBC), blood cultures, sputum culture, and sometimes a CT scan for complicated cases. Rapid respiratory panels can identify specific viruses including influenza, RSV, and SARS-CoV-2, which helps guide treatment decisions.

Bacterial pneumonia treatment involves antibiotics selected by a clinician based on your age, health, likely organism, and local resistance patterns — there is no one-size-fits-all regimen, and antibiotics should never be self-prescribed or shared. Most patients improve within 48 to 72 hours of starting the right antibiotic. If there is no improvement within about 3 days, a clinician may switch antibiotics or order more testing.

Viral pneumonia treatment is primarily supportive: rest, fluids, fever management, and monitoring. Antiviral medications (such as oseltamivir for influenza, or specific antivirals for severe COVID-19 pneumonia) may be used for certain causes when started early and prescribed by a clinician. Most viral pneumonia in otherwise healthy adults resolves with supportive care.

Hospital treatment is needed for a meaningful share of community-acquired pneumonia cases. Indications for hospitalization include low oxygen saturation, significant dehydration, confusion, very high or very low blood pressure, and inability to take oral medications. Severe cases may require ICU admission and breathing support.

When to See a Doctor

Schedule a medical visit if you have a cough that persists or worsens after about a week, a fever that lasts more than a couple of days, shortness of breath with routine activities, or chest pain when breathing. Seek same-day evaluation for any high-risk individual (older adults, immunocompromised people, or very young children) with respiratory symptoms and fever. For milder respiratory illnesses and triage, a virtual visit can be a reasonable first step — see our guides to telehealth for bronchitis and related respiratory symptoms — but pneumonia that is moderate or severe usually needs in-person evaluation with a chest X-ray and an oxygen check.

Frequently Asked Questions

How long does pneumonia last?

With appropriate treatment, most people start feeling better within 3 to 5 days. Full recovery takes longer than many expect: cough may persist for 2 to 3 weeks, and fatigue can last 4 to 6 weeks or longer. The Mayo Clinic notes that older adults and those with weakened immune systems may take 6 to 8 weeks or more to fully recover.

Is pneumonia contagious?

The germs that cause pneumonia (bacteria and viruses) can spread through respiratory droplets. However, exposure does not always result in pneumonia; many people develop only a cold or mild respiratory infection. Good hand hygiene, covering coughs, staying home when sick, and staying up to date on vaccines all reduce spread.

Can you have pneumonia without a fever?

Yes, particularly in older adults and immunocompromised patients. Pneumonia without fever is more common in people over 65, where confusion, weakness, a fall, or rapid breathing may be the main presenting signs. This atypical presentation is one reason pneumonia in older adults is frequently diagnosed late, and why any concerning change deserves prompt evaluation.

What’s the difference between pneumonia and bronchitis?

Bronchitis is inflammation of the bronchial tubes (airways) and typically produces a cough with mucus, mild fever, and chest discomfort; most acute bronchitis is viral. Pneumonia is an infection of the lung tissue itself (the air sacs) and tends to cause more severe symptoms, including higher fever, significant shortness of breath, and chest pain with breathing. A chest X-ray distinguishes the two. See our overview of bronchitis symptoms for a fuller comparison.

Which vaccines help prevent pneumonia?

Pneumococcal vaccination (now routinely recommended at age 50 and older, and for younger high-risk people) directly targets the most common bacterial cause. Annual influenza vaccination, up-to-date COVID-19 vaccination, and RSV vaccination for eligible older adults all lower the risk of viral pneumonia and of the bacterial pneumonia that can follow a viral infection. Ask your clinician or pharmacist which vaccines you are due for.

Recovery Timeline and What to Expect

Pneumonia recovery is often longer than patients anticipate. Even after the acute infection resolves, the body needs time to repair damaged lung tissue and restore full respiratory function.

Week 1: With appropriate treatment, fever usually breaks within 48 to 72 hours for bacterial pneumonia. Cough and shortness of breath begin to improve but are far from resolved. Energy levels remain very low. Keep taking any prescribed antibiotics exactly as directed, even once you feel better.

Weeks 2-4: Chest pain and shortness of breath gradually improve. Cough persists, sometimes producing mucus, but should be trending better. Many patients return to desk work during this window but are not yet back to normal.

Weeks 4-8: Most patients feel substantially better but still tire more easily than usual. Cough may persist, especially with exertion. Exercise capacity is reduced. A follow-up chest X-ray around 6 to 8 weeks is often recommended for older adults to confirm the pneumonia has resolved and to rule out an underlying condition.

Months 2-3: Full energy and exercise capacity return for most patients. Older adults and those with chronic conditions may take even longer to reach baseline, and some people experience post-pneumonia fatigue lasting several months.

The Bottom Line

Pneumonia is common, treatable, and occasionally dangerous — a combination that demands respect without panic. The key symptoms to watch for are a persistent or worsening cough with colored phlegm, fever, shortness of breath, and chest pain that worsens with breathing. Do not assume a bad cold will simply run its course if symptoms are worsening after a week, especially in older adults, young children, or anyone with chronic health conditions. Treat the emergency red flags — trouble breathing, bluish skin, confusion, coughing up blood, or a very high fever — as reasons to call 911. Early diagnosis with clinician-directed treatment dramatically improves outcomes, and prevention through vaccination remains the best strategy of all.

Sources

• CDC — Pneumonia: causes, symptoms, risk groups, and prevention
• CDC — Pneumococcal Vaccination: routine recommendation at age 50+, available vaccines (PCV15, PCV20, PCV21/Capvaxive, PPSV23)
• Mayo Clinic — Pneumonia: symptoms, complications, recovery, and when to seek care
• MedlinePlus / U.S. National Library of Medicine: patient overview of pneumonia
• World Health Organization: fast breathing as the key indicator of childhood pneumonia
• National Library of Medicine (StatPearls): bacterial causes and clinical overview of pneumonia