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Medically reviewed guide · Last updated: 1 August 2026 · Reading time: approx. 9 min
Coughing Up Blood: Why Blood in Your Sputum Always Needs Checking
At a glance
Coughing up blood (haemoptysis) always needs to be checked— even when it was only a single red streak and you feel perfectly well otherwise.
The most common causes are harmlessa small blood vessel bursting after violent coughing fits, or a severely inflamed bronchial lining in bronchitis. That reassurance comes with an instruction attached — go and have it looked at anyway.
The first question before all others: is the blood coming from the lungs at all?A nosebleed that runs down the back of the throat, and blood from the stomach or oesophagus, are regularly mistaken for it.
Anticoagulants make any source of bleeding worse.So never stop them on your own initiative — not even during a bleed. That decision always belongs in medical hands.
Have it checked immediatelylarger amounts of blood rather than single streaks, breathlessness, chest pain, a racing heart, circulatory weakness or pallor — in these cases call 112 (emergency services in Germany) and do not wait for an appointment.
Where is the blood coming from? The three possibilities compared
Before causes can be discussed, the origin has to be clear — it determines everything about the assessment that follows. Blood from the lungs looks different, comes out differently and is accompanied by different complaints than blood from the nose or from the stomach. This overview helps you describe precisely what you have seen; it does not replace an examination.
Origin
What the blood looks like
How it comes out
Typical accompanying signs
First step
From the lungs or the bronchi (haemoptysis)
Bright red, often frothy, sometimes mixed with mucus
When coughing, with an urge to cough beforehand
Cough, sometimes chest pain, sometimes breathlessness
See a doctor promptly; call 112 if breathless
From the nose or the sinuses
Bright red, no froth, often runny
Runs down the back of the throat, is cleared or spat out
Blocked nose, blood from the nostril as well, pressure in the face
Treat the cause in the nose, watch how it develops
Blood that comes from the lungs is usually bright red and frothy, because coughing whips it up with air — and it comes with an urge to cough, not with nausea. Blood from the stomach or oesophagus, by contrast, looks darker, up to coffee-ground-like, because stomach acid alters the red blood pigment; it comes up when vomiting and often goes together with black, tarry stools — you will find pointers on that under Blood in stool.
The third possibility is the one most often overlooked: a nosebleed that does not drip out at the front but runs down the back of the throat. It is then cleared, coughed or spat out and looks deceptively like coughing up blood. A typical clue: it happens above all when lying down, there is no urge to cough beforehand, and there are crusts in the nose.
This distinction is a guide for your conversation at the practice, not a way of ruling anything out. If you are unsure, assume it is coming from the lungs — and have it checked.
The causes in detail
Severe coughing and bronchitis: the most common case
Persistent, forceful bouts of coughing put strain on the small vessels of the bronchial lining. In acute bronchitis that lining is also inflamed, well supplied with blood and vulnerable — and then one violent coughing fit is enough for a small vessel to burst. The result is single red streaks in the sputum, usually over one or two days, after which it disappears again.
That is the most common explanation, and usually that is all it is. The instruction still stands: an appointment at the practice confirms the harmless explanation — or picks up something else early. What else can lie behind a persistent cough is set out in the article on that subject.
Pneumonia and other infections
With pneumonia, the sputum can be stained rust-brown or streaked with blood. It is accompanied by a high fever, shivering chills, marked weakness and often chest pain that varies with breathing. This combination needs to be examined promptly, not only because of the blood but because of the overall picture.
Pulmonary embolism: the combination that counts
In a pulmonary embolism, a blood clot carried in from elsewhere blocks a vessel in the lung. Coughing up blood is not the leading symptom here, but it is an important piece of the puzzle — above all in combination.
Sudden breathlessness + chest pain that varies with breathing + coughing up blood = 112. The risk is increased by long periods of bed rest, recent operations, plaster casts, long journeys by plane or car, cancer, pregnancy and the weeks after giving birth, as well as by a swollen, painful calf on one side. In this situation, do not wait to see whether it gets better.
Lung cancer: named honestly, without panic
Coughing up blood is one of the symptoms that raise the thought of a tumour of the airways — which is precisely why the rule about having it checked is so strict. But the proportions belong in the right perspective: a single trace of blood in the middle of a respiratory infection has a harmless cause as a rule.
The picture that makes imaging urgent looks different: many years of smoking or a smoking history, older age, repeated coughing up of blood without an infection, together with unintended weight loss, persistent hoarseness or a cough that has changed over weeks. If that applies, imaging and usually a bronchoscopy are part of it — not because it is likely, but because early detection is what makes the difference here.
Bronchiectasis and tuberculosis
Bronchiectasis means permanently widened bronchi in which secretions collect. Typical features are large amounts of sputum over years, recurring infections and repeatedly blood-stained secretions. Tuberculosis is rare in Germany but does occur — it is considered where there has been a cough for weeks with night sweats, fever and weight loss, for instance after a stay in a region with a high burden of disease. Both are treatable if they are recognised.
Rarer causes
These include vascular malformations in the lung, autoimmune conditions involving the pulmonary vessels, pronounced heart failure with a back-up of blood, and injuries after procedures on the airways. Rare — but a reason to have unexplained haemoptysis assessed by a specialist.
Observing yourself: judging the amount and the pattern
These observations do not replace a diagnosis. But they help you judge the urgency correctly and describe precisely at the practice what has happened.
Get a rough sense of the amount: single red streaks or spots in the sputum are something completely different from pure, bright red blood. Several tablespoons of blood, or bleeding that does not stop, is an emergency — call 112.
Count how often: once, on several days in a row, or again and again over weeks? Repeated coughing up of blood without a recognisable infection raises the urgency considerably.
Note the circumstances: after violent coughing fits, after physical exertion, in the morning, when lying down, after a nosebleed or after dental treatment?
Check for accompanying symptoms: breathlessness, chest pain, fever, a racing heart, dizziness, a swollen calf, unintended weight loss, night sweats.
Take a photo. A picture of the tissue or of the sputum says more at the appointment than any description — colour and amount are hard to reconstruct afterwards.
Put your medicines together: above all anticoagulants, antiplatelet medicines and NSAID-type painkillers, each with its dose.
Warning signs: when you should not wait
Larger amounts of blood rather than single streaks — or blood that does not stop
Breathlessness, very rapid breathing or bluish lips
Sudden chest pain that varies with breathing
A racing heart, dizziness, cold sweats, pallor or feeling about to faint
Coughing up blood while taking anticoagulants
A high fever with shivering chills and marked weakness
Repeated coughing up of blood over weeks, particularly in people who smoke or at an older age
Coughing up blood with unintended weight loss, night sweats or persistent hoarseness
Emergency: call 112 immediately With larger amounts of blood, with breathlessness or with circulatory symptoms such as a racing heart, pallor and dizziness, call 112 (emergency services in Germany) straight away. Sit the person affected up with their upper body raised and do not leave them alone. The combination of sudden breathlessness, chest pain and coughing up blood points to a pulmonary embolism and allows no delay.
The care pathway: step by step
With coughing up blood, what happens next depends on the amount, the accompanying symptoms and your history. Going via the GP practice is the normal route — with warning signs it is skipped.
Establish the urgency. Any warning signs? Then the emergency number or the emergency department. Without warning signs: a prompt appointment at the GP practice, as a rule within a few days.
History and examination. How much, how often, since when, under what circumstances? Plus listening to the chest, oxygen saturation, blood pressure, pulse and a look into the nose and throat to narrow down the source of the bleeding.
Laboratory tests and imaging. Full blood count, inflammatory markers and clotting values — with vitamin K antagonists, the INR. A chest X-ray is the usual first imaging step; if the findings are unclear, a computed tomography scan follows.
Specialist assessment. If the cause remains open or the bleeding recurs, respiratory medicine takes over — often with a bronchoscopy, which can provide the source of the bleeding and a tissue sample at the same time.
Treat the cause, not the symptom. Antibiotics for a bacterial infection, anticoagulation for a pulmonary embolism, targeted treatment for a tumour or for bronchiectasis. Any change to blood-thinning treatment is always decided by the treating practice.
What to bring to the assessment A photo of the blood-stained sputum, a complete list of your medicines with active ingredients and doses, your notes on the amount and how often it happened, and previous findings such as old X-rays or your last INR. How to keep that list up to date is set out in the guide Keeping a medication list.
The medication angle: anticoagulants and a tendency to bleed
Blood thinners make any source of bleeding worse
Anticoagulants do not usually cause coughing up blood themselves — but they turn a small source of bleeding into a visible one, or a visible one into a threatening one. That applies to the vitamin K antagonist phenprocoumon just as much as to the direct oral anticoagulants rivaroxaban and apixaban. With phenprocoumon it is also worth looking at the INR: if it is above the target range, that is an explainable and correctable cause.
Never stop them on your own initiative Anticoagulants protect against stroke, thrombosis and pulmonary embolism. Anyone who drops them themselves during a bleed trades one risk for a possibly greater one. With coughing up blood too, the rule is: have it clarified medically first, then decide. What else to bear in mind in everyday life is explained in the guide Living with blood thinners.
Antiplatelet medicines and NSAIDs
Low-dose acetylsalicylic acid inhibits the platelets irreversibly, for the rest of their lifespan, and increases the tendency to bleed without your noticing anything in everyday life. Anti-inflammatory painkillers such as ibuprofen also affect platelet function temporarily. It becomes critical in combination: acetylsalicylic acid plus an NSAID, or an NSAID plus an oral anticoagulant — a constellation that arises more often than many people realise, because over-the-counter painkillers rarely appear on the medication list. So when you are being assessed, mention everything you take without a prescription as well. Whether a combination is adjusted is decided by the treating practice, weighing up the risk of thrombosis against the risk of bleeding.
What to keep an eye on
Anyone taking anticoagulant medicines should watch out, alongside coughing up blood, for other signs of bleeding: frequent nosebleeds, bleeding gums, unusually many bruises, dark stools or reddish urine. If several of these occur at the same time, that is a reason for a prompt appointment — regardless of how much blood there was in each individual case.
Keep your anticoagulants under control
Active ingredient, dose and time of day ready to show at any moment — including in the emergency department.
Stopping smoking — in the long run it lowers the risk of lung cancer and chronic bronchitis and reduces the number of coughing fits that injure small vessels.
See infections through properly — the shorter the time the inflamed lining is irritated, the less often a small vessel bursts. Where antibiotics have been prescribed, finish the course as agreed.
Have your clotting values checked — with phenprocoumon the INR regularly, with the direct anticoagulants your kidney values and a dose adjustment as directed by your doctor.
Do not take over-the-counter painkillers casually — NSAIDs need to be discussed while you are on anticoagulants, not taken on impulse from the medicine cabinet.
Actively lower your thrombosis risk — move about on long journeys, stick to the prophylaxis prescribed after operations, take a swollen calf seriously.
No missed dose, no missed check
Reminders for anticoagulants and appointments for your next INR.
Yes. The most common explanation is harmless — a small vessel bursting during heavy coughing. The rule still applies, because the rarer causes include conditions where early detection is crucial. Without warning signs a prompt appointment at the GP practice is enough; you do not need to go to the emergency department.
Blood from the lungs is usually bright red, frothy and comes up when you cough, often mixed with mucus. Blood from the stomach or oesophagus looks darker, up to coffee-ground-like, comes up when you vomit and often goes together with nausea, abdominal pain or black stools. If you are unsure, assume the more serious of the two and have it checked.
Yes, and it is one of the most common mix-ups. If the blood runs down the back of the throat, it is cleared or spat out and looks like coughing up blood. Pointers to the nose as the source are symptoms mainly when lying down, no urge to cough, crusts in the nose and blood that also comes out at the front.
No, not on your own initiative. Anticoagulants protect against stroke, thrombosis and pulmonary embolism; stopping them off your own bat can be more dangerous than the bleeding. Instead, seek medical advice promptly, take your medication list with you and let the decision be made about whether the dose or the active ingredient is adjusted.
With larger amounts of blood rather than single streaks, with breathlessness, with sudden chest pain that varies with breathing, and with circulatory symptoms such as a racing heart, pallor, cold sweats or feeling about to faint. Then call 112, sit the person affected up with their upper body raised and stay with them.
In most cases, no. A single trace of blood during a respiratory infection has a harmless cause as a rule. More attention is paid where blood is coughed up repeatedly without an infection, with many years of smoking, at an older age and with accompanying symptoms such as weight loss, hoarseness or night sweats. Imaging and usually a bronchoscopy are then part of it.
The most helpful things are a photo of the blood-stained sputum, a complete list of all your medicines with active ingredient and dose including anything bought without a prescription, notes on the amount and how often it happened, and previous findings such as older X-rays or your last INR. Colour and amount can hardly be described reliably after the event.
Gesundheitsinformation.de (IQWiG, the German Institute for Quality and Efficiency in Health Care): Cough, bronchitis and pneumonia. Accessed 2026.
gesund.bund.de (German national health portal): Coughing up blood, pulmonary embolism and lung cancer. Accessed 2026.
MSD Manual, Consumer Version: Haemoptysis and vomiting blood. Accessed 2026.
German S2k guideline on the diagnosis and treatment of adult patients with cough (DGP, AWMF register) — German source. Accessed 2026.
German S2k guideline on the diagnosis and treatment of venous thrombosis and pulmonary embolism (AWMF register) — German source. Accessed 2026.
Summaries of product characteristics for the active ingredients mentioned (phenprocoumon, rivaroxaban, apixaban, acetylsalicylic acid, ibuprofen). Accessed 2026.
This article is for general information and does not replace medical advice, diagnosis or treatment. The self-observations described are a guide only and not a diagnosis. Blood in your sputum should always be checked by a doctor; if there are larger amounts of blood, breathlessness, chest pain or circulatory weakness, please contact the emergency services immediately.
