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New HCM diagnosis. Worst symptom is mucus buildup. Is this normal?
First visit with cardiologist last week since diagnosis. I’m overwhelmed with information. Started on 3 RX, a first for me. I’ve been plagued by mucus build up in my throat that really interferes with my sleep. I’m wondering how common this is and if I should pursue with a doc. Any thoughts would be appreciated.
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Interesting. I too have mucus in my throat but I never related it to my HCM in any way.
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1 ReactionCardiomyopathy can lead to a cough and mucus buildup in the throat due to fluid backing up in the lungs and airways, written in a way that’s medically accurate and easy to follow.
Why Cardiomyopathy Causes Mucus in the Lungs:
Cardiomyopathy — whether HCM, DCM, or restrictive — can weaken or stiffen the heart. When the left ventricle cannot pump or fill effectively, blood backs up into the lungs.
This creates two processes:
1. Pulmonary Congestion (Fluid Backup).
When pressure rises in the pulmonary veins:
Fluid leaks from blood vessels into the air sacs.
Fluid mixes with surfactant.
This creates frothy or white “mucus”.
Lungs become irritated → airway glands produce more mucus.
Even though patients think it’s “phlegm,” much of it is actually fluid from congestion, not infection.
This is classic in:
Acute heart failure.
Hypertrophic cardiomyopathy with high filling pressures.
Diastolic dysfunction.
Mitral regurgitation caused by SAM in HCM.
2. Bronchial Mucus Gland Stimulation:
When the lungs are congested, the airway lining senses irritation.
This triggers:
Cough.
Thickened sputum.
“Rattling” feeling.
Worse when lying flat (orthopnea).
Episodes at night (PND).
Congestion makes airway glands overproduce mucus, especially in the larger bronchi.
What the Mucus Usually Looks Like.
Patients often report:
Clear or white mucus (most common).
Foamy sputum (very characteristic of pulmonary edema).
Occasional pink tinge if capillaries are stressed.
This is very different from:
Yellow/green infection mucus.
Thick plugs from asthma/COPD.
Why It Happens Specifically in Hypertrophic Cardiomyopathy (HCM):
HCM can raise filling pressures because:
Thick stiff ventricle → doesn’t relax well.
Mitral valve SAM → causes regurgitation.
Outflow obstruction → increases pressure against which the LV pumps
Any of these can elevate pressure in the left atrium → pulmonary veins → lung tissue.
Even if ejection fraction is normal, diastolic pressure is often high in HCM, which is enough to cause fluid/mucus.
Symptoms Patients Often Notice:
Shortness of breath.
Cough with clear sputum.
Difficulty breathing when lying flat.
Waking up at night coughing.
Wheezing not caused by asthma.
Chest tightness from congestion.
What Helps Reduce the Mucus (Medically):
The goal is to lower lung pressure, not treat it like an infection.
Effective treatments include:
Diuretics (e.g., furosemide) → pulls fluid out.
Beta-blockers → reduce filling pressures in HCM.
Avoiding excess salt.
Treating any mitral regurgitation/SAM.
Lowering blood pressure.
Optimizing HCM medications (metoprolol, verapamil, etc.).
Treatments NOT very helpful:
Antibiotics (unless infection).
Mucus-thinning meds alone (don’t fix the cause).
Cough syrups (just mask symptoms).
Main Cause of HCM:
1. Genetic Mutations (Most common — ~60–70% of cases).
HCM is usually caused by mutations in the genes that build the heart’s sarcomere, the contractile unit of heart muscle.
The most commonly affected genes include:
MYH7 (β-myosin heavy chain).
MYBPC3 (myosin-binding protein C).
TNNT2, TNNI3, TPM1, ACTC1, etc.
These mutations cause the heart muscle—especially the interventricular septum—to thicken abnormally.
Genetic HCM is inherited in an autosomal dominant pattern.
Meaning: a single copy of the mutated gene can cause the condition.
Less Common Causes:
These are NOT the “main” causes but can produce an HCM-like appearance (“phenocopies”):
2. Metabolic or storage diseases.
Fabry disease.
Amyloidosis (AL or ATTR).
Glycogen storage diseases like Pompe.
3. Mitochondrial disorders.
4. Noonan syndrome and related RASopathies.
5. Chronic high blood pressure or aortic stenosis.
These cause hypertrophy, but not true HCM (different mechanism).
Key Point:
True HCM = a genetic sarcomere disease.
This is the main cause unless proven otherwise.
Alcohol is harmful for people with (HCM), as it can also cause mucus buildup in the lungs.
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4 ReactionsWhat is the difference between HCM and ASH
Hello @myhearthealth24,
I am guessing the acronym ASH you refer to is Asymmetric Septal Hypertrophy?
Based on my limited knowledge and ability to use the internet for research, I found this short answer to your question:
Types:
Hypertrophic cardiomyopathy can be classified based on the distribution of the heart muscle thickening:
Asymmetric septal hypertrophy: This is the most common type of HCM, where the septum, the wall between the left and right ventricles, becomes abnormally thickened.
Concentric hypertrophy: In this type, the thickening of the heart muscle is more uniform throughout the left ventricle.
Apical hypertrophy: This type is characterized by the thickening of the heart muscle in the apex (tip) of the left ventricle.
I hope that answers your question. Do you have HCM?
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1 ReactionYour information is helpful and I find the more i understand my diagnosis the better I do. Thank you
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2 ReactionsI am suffering hayper trafic cardio mayopathi 1 Grade MR
My doctor restricted to me any type of fluid tek 1 letter within on day because pressure on lungs
@raj1970 ,
Hello.
It looks like this is your first post here on Mayo Clinic Connect.
I noted from your profile in 2025, that you are in India:
"I reside in Nagaon, near Kolhapur City in Maharashtra, India."
Is your doctor educated in Hypertrophic Cardiomyopathy (HCM)?
MR (Mitral Regurgitation) is common in HCM, and it can become worse as HCM progresses.
Are you near a Center of Excellence (COE)?
I confess...I do not know where Nagaon is.
I've posted a link below for you to read that you may find helpful:
https://www.mayoclinic.org/diseases-conditions/hypertrophic-cardiomyopathy/symptoms-causes/syc-20350198
I hope that you are able to learn as much as you can about this condition. HCM is difficult to diagnose sometimes, and for many patients, they are untreated for years because HCM can mimic many other conditions of the heart.
I am curious about fluid restrictions your doctor put on you...for a lot of HCM patients we are told to stay very hydrated to help with symptoms.
Always follow your doctors advice, of course, but also, educate yourself so you can help in decision making going forward.
How long have you known you have HCM?
Does anyone else in your family have this? It is hereditary.
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1 ReactionMy self
Rajendra Kakaso Patil
Age: 56 years
Height: 174 cm
Weight: 95 kg
Address: Nagaon, Kolhapur, Maharashtra, India – 416122
Occupation:
Since 1988 working in a private company (all types of work) and also a farmer.
Diagnosis:
Hypertrophic Cardiomyopathy (No LVOT obstruction)
Dilated Left Atrium
Mild Pulmonary Arterial Hypertension
Grade I Mitral Regurgitation
Grade II Tricuspid Regurgitation
PASP: 77 mmHg
Normal Left Ventricular Systolic Function
Current Treatment:
BisoT 5/40 – 1 tablet daily
Atorva ASP 75 mg – 1 capsule daily
Dytor Plus 5 mg – 1 tablet daily
Advice:
Fluid restriction: 1 litre per day
Any suggestions please
@tommy901
Thanks so much for your description! I had a myectomy for HOMC seven weeks ago. In the last several months I had begun to have asthma like symptoms (rattle) even though previous allergy tests showed absolutely no allergies. I talked to my primary doctor and he was not overly concerned. I now realize that it is exactly what you are describing and I have not experienced these symptoms since my surgery. Thank you for helping me make this connection. I’m thrilled to be rid of one more additional problem!
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