What causes blood in phlegm but no cough?

blood in phelgm no cough
Medically reviewed by Dr. Mandy Liedeman


Coughing up blood can be a concern, especially as you age or if you smoke. While it’s often due to prolonged coughing or dry airways, it may also occur in individuals taking anticoagulants. However, additional symptoms like shortness of breath, fever, or discolored phlegm could indicate a more serious condition, such as a respiratory infection or bronchitis. 

Why is there blood in my phlegm without coughing?

Coughing up blood in phlegm can be alarming, indicating various underlying conditions. Understanding each cause and its treatment is crucial for proper management. Here’s an in-depth look at potential causes and their corresponding treatments:

  1. Respiratory Infections

Infections such as pneumonia or tuberculosis can cause inflammation and irritation of the airways, leading to blood in phlegm. Also, fungal respiratory infections can cause yellow or green mucus with blood.


  • Antibiotics: Antibiotics such as amoxicillin may be prescribed for bacterial infections like pneumonia to treat the infection and reduce inflammation. 
  • Antiviral Medications: Antiviral medications may be prescribed for viral infections like influenza to reduce symptoms and duration of illness.

  1. Dried Airways

If you are experiencing blood in sputum in the morning when clearing your throat, dry airways may be the reason. Dry air from environmental factors or illnesses can dry out the airways, leading to irritation and potential bleeding.


  • Anti-inflammatory Medications: Over-the-counter anti-inflammatory medications like ibuprofen or corticosteroid nasal sprays can help reduce inflammation in the airways.
  • Maintain Hydration: Drink adequate fluids throughout the day to moisten the airways and prevent dryness.
  • Nasal Irrigation: Use saline nasal sprays or a neti pot to irrigate the nasal passages and maintain moisture.
Worried about blood in your phlegm? Get connected with virtual healthcare providers for effective diagnosis and treatment options!

  1. Anticoagulant Medications

Another cause of coughing blood in phlegm can be anticoagulant medications such as warfarin or heparin, which can increase the risk of bleeding, including bleeding in the respiratory tract.


  • Monitoring: Regular monitoring of anticoagulant therapy is essential to ensure proper dosing and minimize the risk of bleeding complications.
  • Small Amounts of Blood: Small amounts of blood in phlegm may not be concerning but should be monitored closely.
  • Medical Assessment: Seek medical evaluation if significant bleeding occurs, as adjustments to anticoagulant therapy may be necessary.

  1. Persistent Coughing

You may be suffering from persistent coughing due to allergies, flu, or respiratory infections can lead to irritation and inflammation of the airways, resulting in streaks of blood in phlegm. 


  • Corticosteroids: To get rid of chronic persistent cough, your doctor may prescribe medications like corticosteroids for effective treatment such as prednisone, prednisolone, and dexamethasone.
  • Antihistamines: Over-the-counter (OTC) antihistamines like loratadine, cetirizine, and fexofenadine can help reduce allergy symptoms and alleviate coughing.
  • Homemade Cough Remedies: Try natural cough remedies such as honey, lemon, or ginger to relieve coughing and soothe the throat.

  1. Bronchiectasis

Bronchiectasis is a chronic condition characterized by the abnormal widening of the bronchial tubes, leading to excessive phlegm production and potential bleeding.


  • Prescription medications: Medications such as bronchodilators or mucolytics may be prescribed to alleviate symptoms and reduce phlegm production.
  • Pulmonary Rehabilitation: Pulmonary rehabilitation programs may help improve lung function and quality of life for individuals with bronchiectasis.

  1. Pulmonary Edema

Blood in phlegm may be due to pulmonary edema, which occurs when fluid accumulates in the lungs, often due to heart failure or other cardiac conditions, leading to coughing up pink or red-tinged phlegm.


  • Medical Emergency: Pulmonary edema is a medical emergency and requires immediate medical attention.
  • Hospitalization: Hospital admission may be necessary for treatment, including oxygen therapy, diuretics to remove excess fluid, and medications to improve heart function.

  1. Lung Cancer

Lung cancer can cause coughing up blood, especially in smokers or individuals with a history of lung disease.


  • Early Detection: Early detection and treatment offer the best chance of successful outcomes.
  • Treatment Options: Treatment options for lung cancer may include surgery, chemotherapy, radiation therapy, targeted therapy, or immunotherapy, depending on the type and stage of cancer.

Treating blood in phlegm without coughing involves addressing the underlying cause with appropriate medical management. It’s essential to seek medical evaluation and avoid self-diagnosis or treatment.

How long does blood in phlegm last?

Blood in mucus that lasts longer than a week is severe, may worsen over time, and require immediate medical attention. While most cases of blood in phlegm resolve independently, monitoring the duration and severity of symptoms is essential.

The blood mucus is typically from the lungs and can result from prolonged coughing or a chest infection. In the majority of cases, the bleeding will stop spontaneously. However, in about five percent of individuals experiencing their first episode of coughing up blood, the bleeding may be severe.

If you experience persistent or worsening blood in phlegm, or if it comes and goes over time, contact your doctor for further evaluation and appropriate management.

Get connected with an online doctor to get an accurate diagnosis and well-suited treatment options!

When should I be worried about blood in my phlegm?

Blood in phlegm can be alarming and may indicate an underlying medical issue. Here’s when you should seek medical attention for blood in your phlegm:

  • If you cough up more than a few teaspoons of blood
  • If you experience chest pain, dizziness, fever, light-headedness
  • If you feel shortness of breath getting worse along with coughing up blood

While blood in the sputum is common in mild respiratory conditions like upper respiratory infections and asthma, it can also signal more serious problems such as bronchitis or lung cancer. In approximately half of all cases, doctors cannot identify a specific cause, highlighting the need for thorough medical evaluation when symptoms arise.

FAQs about blood in phlegm, no cough

Can a sinus infection cause blood in mucus?

Yes, in chronic, acute, subacute, and recurrent sinusitis caused by bacteria, viruses, fungi, or allergies, the mucous membranes become congested and edematous, causing the nasal mucosa to bleed easily. The blood is more prone to bleeding, especially when sinusitis is severe and prolonged.

Is coughing up blood serious?

Yes, coughing up blood can indicate a serious condition. Immediate hospitalization may be necessary until doctors stop the bleeding. Doctors will evaluate your symptoms, condition, and history, which may include a physical exam and checking your chest and lungs.

Is a little blood in phlegm normal?

While coughing up blood can be alarming, it isn’t necessarily a sign of a serious problem. However, it’s more concerning, especially as you age or if you smoke. If you cough up blood, you must see your GP immediately for evaluation and appropriate management.

Your Doctors Online uses high-quality and trustworthy sources to ensure content accuracy and reliability. We rely on peer-reviewed studies, academic research institutions and medical associations to provide up-to-date and evidence-based information to the users.

  • Liu, Ren, et al. “Study on syndrome differentiation strategy of phlegm and blood stasis syndromes of coronary heart disease based on expert consultation on medical cases.” Annals of Palliative Medicine 10.9 (2021): 9940-9952.
  • Butler, Lesley M., et al. “Dietary fiber and reduced cough with phlegm: a cohort study in Singapore.” American journal of respiratory and critical care medicine 170.3 (2004): 279-287.
  • Shen, Yi, et al. “Effect of Bairui Granule on Inflammatory Mediators in Induced Sputum, Leukotriene C4, and EOS in Peripheral Blood of Children with Cough Variant Asthma.” Computational and Mathematical Methods in Medicine 2022 (2022).
  • Souter, Jacqui. “OTC products for: Cough Preparations.” SA Pharmacist’s Assistant 6.4 (2006): 10-14.

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