Color should be considered together with other factors, including duration, severity, fever, breathing difficulties, chest pain, and overall health.

What About Blood in Phlegm?

Blood-streaked mucus can sometimes occur after intense coughing because the small blood vessels in irritated airways can break.

But coughing up blood should not simply be dismissed, particularly when the amount is more than a small streak or when it happens repeatedly.

Possible causes range from respiratory infections and airway irritation to more serious lung conditions.

Seek prompt medical attention if you cough up significant amounts of blood or experience blood in your mucus alongside:

• Difficulty breathing
• Chest pain
• Dizziness or fainting
• Severe weakness
• Rapid worsening

When Should You See a Doctor?

Occasional phlegm is usually not a reason for alarm.

However, persistent respiratory symptoms deserve attention.

Consider speaking with a healthcare professional if you have:

A cough lasting several weeks

Persistent or increasing phlegm

Repeated respiratory infections

Unexplained weight loss

Persistent fever

Shortness of breath

Chest pain

Wheezing

Repeated blood in mucus

For people with a history of smoking, long-term respiratory symptoms are particularly important to discuss with a clinician.