A Guide to Distinguish Among Different Respiratory Infections
Do you cough, sneeze, have an itchy or sore throat, difficulty breathing, fever, or you cough up mucus and you do not know what disease you might have? In the table below, you can check when certain respiratory infections appear, how they are spread, and what are their common and unlikely symptoms.
Table: Characteristics of common respiratory infections
- *unlikely symptoms = those that do not or rarely appear in a listed disease
- **droplet = infection through droplets of saliva or mucus expelled into the air during speaking, coughing, sneezing. Droplets may stay on surfaces (door knobs, keyboards, etc.) for several hours
- ***nodes = lymph nodes (glands)
|DISEASE and CAUSE||SEASON and TRANSMISSION||COMMON SYMPTOMS||UNLIKELY SYMPTOMS*|
|COMMON COLD – RHINITIS; rhinoviruses, coronaviruses, RSV and other viruses||Late August to April, also in summer; droplet**, human-to-human||Blocked nose with watery to thick green discharge, wet eyes, itchy throat, dry cough, (sometimes low-grade fever or headache); lasts 1 week||Body aches, rash, enlarged nodes***|
|ACUTE SINUSITIS; various viruses, bacteria, fungi (also pollutants or allergy)||Winter; complication of existing viral disease; sinusitis as a disease is not contagious||Pressure and tenderness in cheeks and/or front, headache, blocked nose, thick green mucus (thin mucus in allergy), post-nasal drip, or swollen eyelids; lasts less than 4 weeks||Body aches, swollen nodes, rash|
|SEASONAL FLU; Influenza A or B virus||November- April, occasionally in summer (in travelers) (1); droplet, human-to-human||Body aches, headache, tiredness, blocked, runny nose, sore throat, dry cough, high fever (101-105°F =38-40.5°C, rarely no fever at all), lasts 1-2 weeks||Swollen nodes, rash (in severe flu), pneumonia (in small children, old, chronic patients)|
|SWINE (NEW, 2009 PANDEMIC) FLU; Influenza A virus, subtype H1N1||Year-round; 2009 summer flu cases were probably swine flu (2); droplet, human to human, rarely humans to pets (3), rarely pigs to humans||Symptoms, like in seasonal flu, but pneumonia is possible also in young and otherwise healthy individuals, often no fever (4)||Swollen nodes, rash|
|BIRD FLU – AVIAN INFLUENZA; Influenza A virus, subtype H5N1||Year-round (5), from wild or domestic birds or pigs to human, not human-to-human||Symptoms, like in seasonal flu, but pneumonia is possible also in young and otherwise healthy individuals||Swollen nodes, rash|
|DIPHTERIA; bacterium Corynebacterium diphtheriae||Year-round, droplet, human to human, rare in US and Europe||Difficulty breathing, slurred speech, double vision, sore throat, swollen neck nodes, black throat membranes; lasts two weeks||Body aches|
|MONO – INFECTIOUS MONONUCLEOSIS; Epstein-Barr virus (EBV), Citomegalovirus (CMV)||Year-round, close contact (kissing) by infected person||Swollen lymph nodes in the neck, armpits and groin, sore throat, fatigue, fever, rash, enlarged spleen; mostly young adults; lasts 1-4 months||Runny nose, pneumonia|
|STREP THROAT; bacterium Streptococcus pyogenes||Late autumn to early spring, but may be year-round; droplet, human to human||Sore throat, difficult swallowing, swollen, reddened tonsils, cough, enlarged nodes behind the ears and in neck, high fever, headache, mostly children 5-15 y/o; lasts up to one week||Body aches|
|VIRAL PHARYNGITIS; influenza virus, adenovirus, Herpes simplex, EBV, CMV, RSV, HIV||Year-round; droplet, human to human||Sore, reddened throat, often (not always) runny nose, fever; last few days to few weeks||Body aches|
|VIRAL LARYNGITIS; viruses (influenza, measles, mumps, etc.)||Year-round, mostly in winter; as complication of existing infection; laryngitis itself is not contagious||Hoarsness or lost voice, soreness around Adam’s apple, dry cough, difficulty breathing (in children); lasts 3 days - a week||Body aches, rash|
|CROUP; parainfluenza virus, RSV||Year-round, droplet, human to human||Barking cough, hoarsness, continues with runny nose, in children, lasts about a week||Body aches, rash|
|WHOOPING COUGH – PERTUSIS; bacterium Bordetella pertussis||Year-round||Runny nose (1-2 weeks), followed by whooping cough, alltogether lasts 3-10 weeks||Body aches, swollen nodes, rash|
|CHILDHOD INFECTIONS WITH RASH: Chicken pox (Varicella zoster), Measles (Rubeolla virus), German measles (Rubella virus), Erythema infectiosum or ‘fifth’ disease (Parvovirus B19), Scarlet fever (bacterium Streptococcus group A)||Year-round, skin contact or droplet infection, human to human||Rash, fever, sore throat, dry cough, red eyes, headache, tiredness, abdominal pain, diarrhea; children < 15 y/o; last 5-14 days||Swollen nodes in armpits or groin|
|TUBERCULOSIS; Mycobacterium tuberculosis||Year-round; droplet, human to human||Low grade fever, coughing up blood, chest pain, feeling unwell, tiredness; may last for months||Sore throat, runny nose, body aches|
|BRONCHIOLITIS caused by Respiratory Syncytial Virus (RSV)||Autumn-spring; droplet, human to human||Wheezing, rales, dry cough, rapid breathing, fever; small children; lasts few weeks||Enlarged nodes, rash|
|BACTERIAL PNEUMONIA; bacteria: Streptococcus pneumoniae (pneumococcus), Staphylococcus aureus, Neisseria meningitidis, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas, etc.||Winter/spring or year-round; pneumonia itself is usually not contagious, but is a complication of an existing respiratory infection||High fever, rapid and difficult breathing, rapid heartbeat, coughing up yellow, green, frothy or bloody mucus, chest pain; with treatment lasts about a week, non-treated often fatal|
|VIRAL PNEUMONIA; Adenovirus, Influenza virus (all types), coronavirus, measles, varicella…||Year-round, mainly in winter; as a complication of an existing viral infection||Dry cough, fever, feeling unwell, low appetite; lasts up to one month or more|
|ATYPICAL PNEUMONIA; Mycoplasma pneumoniae, and Chlamydia pneumoniae, Legionella pneumophila, etc.||Year-round; droplet, human to human (Legionella: through air condition, water systems in newly opened hospitals…)||Dry cough, sore throat, fever, feeling unwell, tiredness, body aches, night sweats, diarrhea, mostly in young people; lasts up to 1 month or more|
|CMV PNEUMONITIS; (Citomegalovirus)||Year-round; droplet, human to human||Dry cough, difficult breathing, fever; in immunosuppressed patients (AIDS, leukemia); often deadly|
|TOXOPLASMOSIS; unicellular parasite Toxoplasma gondii||Fecal-oral by cat feces, or by eating undercooked pork, lamb or deer meet||Fever, swollen neck nodes, dry cough, tiredness; lasts few weeks/months; in people with lowered immunity (AIDS, cancer) can be fatal|
|Q FEVER; bacterium Coxiella burnetii||From cattle, sheep, or goat milk, feces, saliva to human||High fever, severe headache, muscle pains, confusion, sore throat, dry cough, nausea, vomiting, diarrhea, abdominal pain, chest pain; farmers; lasts few weeks|
|PSITTACOSIS; bacterium Chlamydia psittaci||Year-round, domestic birds secretion inhalation||Fever, severe headache, sore throat, dry cough, difficult breathing; farmers, zoo workers; lasts few weeks/months|
- Hay fever, an allergy to pollens, appears from March to October and may cause runny nose, sneezing, itchy eyes and throat. Symptoms of allergic rhinitis (allergy to molds, dust mites, pollutants) may last year-round. There is usually no fever in allergic reactions.
- Transmission of respiratory infections is usually by inhalation of droplets from infected persons while they cough or sneeze, or by picking viruses from the door knobs, computer keyboards or other contaminated surfaces; rarely by fecal-oral route from animals (bird flu, toxoplasmosis, Q fever)
- Diagnosis. Mild respiratory infections, like common cold or seasonal influenza, are usually diagnosed from symptoms and no other tests are needed. Swine or bird flu are diagnosed by blood tests. A cause of pneumonia is determined by blood and sputum (mucus) tests.
- Apart from infections, other diseases can cause respiratory symptoms: asthma, bronchitis, pleuritis, silicosis, mesothelioma, lung cancer, thyroid disease, panic attack, allergies, heart failure, including heart attack, kidney failure, pulmonary embolism, uncontrolled diabetes, cystic fibrosis, spontaneous or traumatic pneumothorax.
- Treatment. Mild viral respiratory infections do not need any treatment. For different types of flu, appropriate drugs are available. Bacterial infections are treated by antibiotics. Home remedies are not likely to help in respiratory infections.
- Flu in the summer (yourtotalhealth.ivillage.com)
- Flu in the summer 2009 was probably swine flu (abcnews.go.com)
- Swine flu can be transmitted from humans to pets (cdc.gov)
- Swine flu often appears without fever (nytimes.com)
- Bird flu can appear year-round (content.nejm.org)
Article reviewed by Dr. Greg. Last updated on April 9, 2010