About amyloidosis
The disease
An in-depth guide to what amyloidosis is, how it forms, which organs it affects, and how it is treated — written for patients, families, and healthcare professionals.
01
What is amyloidosis?
A protein misfolding disease
Amyloidosis is a group of diseases in which abnormal proteins, called amyloids, fold incorrectly and accumulate in tissues and organs. These misfolded proteins form insoluble fibrils that disrupt normal organ structure and function.
The process begins at the molecular level — a normally harmless protein becomes unstable, changes shape, and begins to aggregate into twisted fibrous structures that the body cannot break down.
Organ deposits
Once formed, amyloid fibrils deposit within the extracellular matrix of organs — essentially filling the spaces between cells. As deposits accumulate, they progressively stiffen tissues and impair the electrical, mechanical, or filtration functions of the affected organ.
The heart becomes stiff and unable to fill normally; the kidneys lose their ability to filter protein; the nerves fail to transmit signals. The range of affected organs and the severity of impact vary significantly by amyloidosis subtype.
02
Understanding amyloid deposits
Unlike most proteins which are cleared from tissues when they become damaged, amyloid fibrils are highly resistant to the body’s normal protein-degradation systems. They accumulate progressively, and their effects compound over time.
Diagnosis typically requires a biopsy with Congo red staining — amyloid deposits show a characteristic apple-green birefringence under polarised light, one of the most specific findings in pathology.
Key clinical insight
Amyloid fibrils can deposit in virtually any organ or tissue. The distribution pattern — which organs are most affected and to what degree — is highly subtype-specific and drives both the clinical presentation and the treatment strategy.
03
How amyloid forms
A step-by-step overview of the molecular pathway from normal protein production to tissue damage.
Step 01
Normal protein
The body produces a normal precursor protein — transthyretin, light chains, SAA or others — as part of routine biological processes.
Step 02
Misfolding
Due to genetic mutation, overproduction, ageing, or chronic inflammation, the protein becomes structurally unstable and misfolds.
Step 03
Amyloid fibrils
Misfolded proteins aggregate and self-assemble into insoluble β-sheet fibrillar structures that resist enzymatic degradation.
Step 04
Organ impact
Fibrils deposit in organ extracellular matrix, displacing normal tissue, stiffening structure, and progressively impairing function.
04
From protein to organ damage
The journey from a misfolded protein to a life-changing diagnosis can take years — even decades. Symptoms are insidious and non-specific, often attributed to ageing or more common conditions, resulting in a diagnostic delay that averages over four years from first symptoms.
Understanding the mechanisms of organ damage — cardiomyopathy, nephrotic syndrome, peripheral neuropathy — is fundamental to recognising the disease early and initiating treatment before irreversible damage occurs.
05
Symptoms and organ impact
A simple body map to help patients and healthcare professionals connect warning signs with the organs affected by amyloidosis. Hover over each hotspot for detail.
Vitreous deposits
Floaters, transient visual disturbances, and vitreous opacities due to amyloid protein accumulation within the eye.
Proteinuria & oedema
Protein spilling into the urine, reduced kidney function, and progressive swelling of the lower limbs from nephrotic syndrome.
Organomegaly
Enlargement of the liver or spleen causing fullness, early satiety, and abnormal liver function tests — a common early finding in AL amyloidosis.
Amyloid fibrils deposit in the vitreous humour, causing characteristic “floaters” and eventually visual impairment. Vitreous amyloidosis is a hallmark feature of hereditary ATTR.
Cardiac amyloidosis causes thickening of the ventricular walls, restrictive cardiomyopathy, and conduction disturbances — presenting as breathlessness, oedema, and arrhythmia.
Amyloid deposition in the renal glomeruli disrupts the filtration barrier, causing heavy proteinuria, nephrotic syndrome, and progressive kidney failure — predominantly in AL and AA.
Amyloid fibrils compress and infiltrate peripheral nerves, causing progressive sensorimotor neuropathy — numbness, tingling, and weakness beginning distally in the hands and feet.
Ankle and lower limb oedema results from cardiac failure, nephrotic syndrome, or both. Bilateral pitting oedema worsening over the day is a key presentation prompting amyloidosis work-up.
Hover hotspots for detail
Cardiomyopathy
Shortness of breath, ankle swelling, and arrhythmia due to restrictive cardiomyopathy caused by amyloid infiltration of the ventricular walls.
Sensorimotor neuropathy
Tingling, numbness, and loss of sensation starting in the lower limbs and ascending — often misdiagnosed as diabetic or idiopathic neuropathy.
Bilateral oedema
Progressive bilateral ankle swelling, often disproportionate to cardiac or renal findings, reflecting multisystem involvement and fluid retention.
06
The diversity of amyloidosis
More than 40 human precursor proteins are known to form amyloid deposits. — each forming its own subtype with distinct clinical presentation, organ targets, genetic background, and treatment pathway.
Amyloid protein
The precursor protein defines the amyloidosis subtype. The most prevalent are: immunoglobulin light chains (AL), transthyretin (ATTR), serum amyloid A (AA), and a range of hereditary variants including apolipoprotein A-I, gelsolin, lysozyme, and fibrinogen A-alpha chain.
Affected organs
Organ tropism depends on the amyloid protein type. AL typically affects heart, kidneys, liver, nerves, and soft tissues. ATTR has a particular affinity for the heart and peripheral nervous system. AA almost exclusively targets the kidneys. Hereditary subtypes vary by gene mutation.
Different types
Amyloidosis can be classified as systemic (widespread organ involvement) or localised (confined to a single tissue such as airways, bladder, or skin). Systemic forms are further divided into acquired (AL, AA) and hereditary (ATTRv, ApoA-I, Gelsolin…), each with distinct inheritance patterns and management strategies.
07
Treating amyloidosis
Treatment depends on the amyloid type. It may aim to reduce production of the precursor protein, stabilise the protein, support affected organs and manage symptoms.
Disease-modifying treatments
Therapies targeting the underlying source of amyloid — chemotherapy for AL (plasma cell suppression), TTR stabilisers and gene silencers for ATTR, anti-inflammatory agents for AA — with the goal of halting further deposition.
Supportive treatments
Management of organ-specific complications: diuretics and anti-arrhythmics for cardiac amyloidosis, ACE inhibitors for renal protection, pain management and physiotherapy for peripheral neuropathy.
Long-term follow-up
Regular surveillance with biomarkers (NT-proBNP, troponin, creatinine), imaging, and quality-of-life assessment to monitor response, detect relapse early, and adjust therapy as disease evolves.
08
Living with a rare diagnosis
Receiving an amyloidosis diagnosis is life-changing. The rarity of the disease means that many patients feel isolated, misunderstood, and uncertain about the future. Preparation, connection, and access to the right information make a profound difference.
Understand your type
The subtype of amyloidosis determines your prognosis, treatment, and the risk for family members. Confirming the exact protein involved — through blood tests, genetic analysis, and biopsy typing — is the essential first step.
Prepare your questions
Use our patient toolkit to structure conversations with your specialist team: what treatment is recommended, what are the goals, how will progress be monitored, and what support services are available locally.