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Reviewed By:

Phillip Aguila

Phillip Aguila, MD, MBA (Respiratory medicine, Critical Care)

Eisaku Kamakura

Eisaku Kamakura, MD (Respiratory medicine)

From our team of 50+ doctors

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People with these symptoms also use Ubie's symptom checker to find possible causes

  • Coughing up green mucus

  • Coughing up phlegm stained with blood

  • Coughing up phlegm

  • Blood stained phlegm

  • Blood-tinged sputum

  • Bringing up mucus

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Content updated on Sep 6, 2022

About the symptom

Phlegm is a form of mucus produced in the lungs. You usually don't produce noticeable amounts of phlegm unless you have a cold or another underlying medical condition. Sputum is the term for phlegm that is coughed up.

When to see a doctor

Seek professional care if you experience any of the following symptoms

  • Repeated fever above 38 ℃

  • Peripheral cyanosis

  • Difficulty breathing / breathlessness

  • Respiratory wheeze

  • Fever

Possible causes

  • Cough variant asthma

    A type of asthma where the main symptom is a persistent dry cough. This is due to the airways being highly sensitive and overreacting to foreign substances. The underlying cause is unclear but involves genetics. There are many triggers for asthma flares, including smoke, pollen, dust mite droppings, cold weather, exercise and viral infections.

  • Common cold (upper respiratory tract infection)

    Viral infection of the nose and throat. Symptoms include coughing, runny nose and throat pain. The majority of colds are caused by viruses; a small number are caused by bacteria instead.

  • Acute / chronic tracheitis / bronchitis

    Inflammation of the airways, usually caused by "flu" viruses spreading to the airways. Symptoms include vigorous coughing, increased phlegm, fever and lethargy. It is usually caused by viruses rather than bacteria.

  • Sinusitis
  • Alzheimer dementia (AD)
  • MRSA infection

Related serious diseases

Questions your doctor may ask about this symptom

Your doctor may ask these questions to check for this symptom

  • Do you have phlegm?

  • Do you have blood in your phlegm?

  • Do you have a cough?

  • Do you have a fever?

  • Do you have a sore throat?

Other Related Symptoms

Similar symptoms or complaints

  • Cough

Symptoms treated by the same specialty

Reviewed By:

Phillip Aguila

Phillip Aguila, MD, MBA (Respiratory medicine, Critical Care)

Eisaku Kamakura

Eisaku Kamakura, MD (Respiratory medicine)

From our team of 50+ doctors

Just 3 minutes.
Developed by doctors.

Ubie is supervised by 50+ medical experts worldwide

Shohei Harase

Shohei Harase, MD


Kameda Medical Center, Japan

Sanshiro Kato

Sanshiro Kato, MD

Emergency department

Kawai Clinic, Japan

Yu Shirai

Yu Shirai, MD


Yotsuya Yui Clinic, Japan

Yoshinori Abe

Yoshinori Abe, MD

Internal medicine

Co-founder of Ubie, Inc.

Rohini R

Rohini R, MD

Ear, nose, throat (ENT)

Bayshore Health Centre, India

Seiji Kanazawa

Seiji Kanazawa, MD, PHD

Obstetrics and gynecology (OBGYN)

National Center for Child Health and Development, Japan

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