Lung cancer is the second most common cancer after breast cancer, and kills more people than any other cancer.
Tobacco smoking is the main cause of lung cancer and about 80-90% of lung cancers can be attributed to it.
Cancer that begins in the lungs is called primary lung cancer, while cancer that spreads to the lungs from another place in the body is known as secondary lung cancer
Lung cancer is an aggressive form of cancer that spreads rapidly.
Early diagnosis and treatment improve a person's chances of living for five years or longer.
With this in mind, being aware of the type of cough - including the colour of your phlegm - could determine your risk.
Early signs of lung cancer
One of the most common early warning signs of lung cancer is a persistent cough.
The cough may not go away after a few weeks, and it could develop into a chronic cough.
If you're coughing up any mucus or phlegm, it's crucial that you check its colour.
Rust-coloured phlegm could be a sign that you should see a doctor straight away.
"Many early lung cancers are diagnosed as an incidental finding with a test for a different purpose," said the Lung Cancer Foundation of America.
"But when they do appear, knowing the warning signs of lung cancer may allow you to get screened earlier.
"Your body induces itself to cough in order to protect any particles from entering your airways and the lungs.
“A cough that doesn’t go away, or worsens into a chronic cough, is one of the most common symptoms of lung cancer.
"If you are coughing up blood or rust-coloured spit/phlegm, see your doctor immediately."
Is coughing up blood a sign of lung cancer?
Coughing up blood from your respiratory tract is referred to as hemoptysis.
It is one of the most common symptoms of lung cancer.
However, coughing up blood is not generally associated with any particular stage of lung cancer over another, according to the American Cancer Society
Despite being linked to a wide range of concerning health conditions, bloody phlegm is often accompanied by other vague symptoms that are known to be caused by lung cancer.
According to the NHS, the most common signs are:
- Persistent cough
- Persistent breathlessness
- Unexplained tiredness and weight loss
- An ache or pain when breathing or coughing
- Coughing up blood.
In addition to these widely recognised symptoms, the American Cancer Society acknowledges further side effects that are also linked to lung cancer.
These include:
- Hoarseness
- Loss of appetite
- Recurring or persistent infections with bronchitis and pneumonia
- New onset of wheezing.
