Thick white phlegm often means you have an infection like the flu, a cold or even bronchitis.
Having thick white phlegm can also have other conditions like asthma or even cystic fibrosis and thick white phlegm can also occur as a result of dehydration or allergies, although most often having thick white phlegm is not a cause for concern.
Although if the thick white phlegm lasts longer than a few days or a week or gets worse or is accompanied by other symptoms like fever, shortness of breath, chest pain or other signs of illness you should see a doctor.
The most common cause of thick white phlegm is a viral infection like the flu or the common cold, which can make your phlegm white and thick and sticky and is a way of getting rid of the germs and bacteria.
Other causes of thick white phlegm are chronic lung diseases like COPD or cystic fibrosis which are associated with excessive thick mucus that can obstruct your airways.
Allergies like exposure to dust or pollen can lead to mucus buildup and lead to thick white phlegm.
Dehydration and not drinking enough fluids can cause mucus to become thicker and more concentrated and white or even other colors.
And inflammation of your airways like from bronchitis or asthma can result in the production of thick white mucus or phlegm.
If the thick white phlegm or mucus lasts longer than a week or the symptoms get worse you should see a doctor.
Or if you're coughing up a large amount of the thick white phlegm or mucus without feeling sick, it can signal an underlying health issue like lung disease or heart disease.
And if you experience a severe cough with the thick white phlegm or mucus or if the thick mucus or thick phlegm is pink or bloody or you have trouble breathing you should seek medical attention immediately.