# Symptoms and phases of IgG4-related disease
IgG4-related disease progresses very differently from person to person, depending on which organs are affected. There is no fixed division into 'stages' like with cancer; instead, one speaks of **phases based on activity**: active (before treatment starts), under treatment, and in remission (without active complaints). At the same time, the disease can spread to other organs. Below we describe how the disease usually presents, what you feel and see in your body, and what we know about its course.
Early phase: first symptoms
In the early phase, many people notice slowly increasing complaints, often without a clear cause. The symptoms depend strongly on which organ is affected, and many patients have **multiple organs simultaneously** dealing with inflammation.
**Most common complaints in this phase:**
- **Swelling of salivary glands** (usually under the jaw, submandibular or parotid gland) — these swellings can be present for months to years before diagnosis is made
- **Eye symptoms**: feeling of sand in the eyes, dry eyes, swelling around the eyes (especially of the tear glands)
- **Abdominal complaints**: diffuse abdominal pain (not in one place), bloated feeling, fluctuating stomach and bowel disorders
- **Neck and sinus complaints**: stuffy nose, sinus inflammation that does not respond well to antibiotics, pain above the eyes
- **Fatigue and general feeling of malaise** — often underestimated, but very distressing for many patients
- **Brief fever** (not high, but persistent)
In this phase, people do not yet have a diagnosis, and symptoms are often attributed to other causes (allergy, viral infection, fatigue). This can last months to years.
**What this means for daily life: **
Many people feel chronically ill without a clear explanation. They may struggle to go to work due to fatigue, eyes can be so dry that reading or screen work hurts, and abdominal complaints can impact meals.
Phase of active disease (diagnosed)
Once the diagnosis is made (usually via biopsy of affected tissue and elevated IgG4 antibody in the blood), it becomes clear that the disease is appearing in multiple places at once. In this phase, inflammation is most prominent.
**Complaints at this time may include:**
- **Pancreatic symptoms** (approximately 30–50% of all patients): abdominal pain especially above the stomach, sometimes radiating to the back; elevated pancreatic enzymes in the blood; grey, fatty or floating stool (fat malabsorption)
- **Kidney symptoms**: usually without noticeable complaints, but present in blood tests as protein in urine or slightly elevated kidney function; sometimes swelling of kidney tissue visible on CT
- **Lymph node inflammation**: swollen lymph nodes in abdomen, neck and chest
- **Lung complaints**: cough (dry or with some mucus), difficulty with exertion, sometimes shortness of breath
- **Neurological symptoms** (rare but serious): e.g. spinal pain or nerve disorders
- **Bowel symptoms**: chronic diarrhea, absorption problems, thickened intestinal wall visible on imaging
- **Swollen lymph nodes in the brain and around nerves** (submandibular area, eyes): can cause pressure
In this phase, many people feel "chronically ill" — much fatigue, sometimes low-grade fever, and symptoms that come and go.
**What this means for daily life: **
People can experience significant limitations. Abdominal pain can make eating difficult, fatigue makes work and family life heavy, and eye complaints can significantly impact quality of life. The diagnosis brings on one hand relief (finally a name!), but also the confrontation with a chronic illness.
**Figures about this phase: **
The average time from first symptoms to diagnosis is often **2–4 years** (this varies greatly; some patients are recognized much earlier, others much later). At the time of diagnosis, approximately **60–70% of patients already have multiple organs affected** (population figures, based on studies from recent years). Little is known about survival at this stage because treatment usually starts quickly, but without treatment the disease can cause severe progressive damage (especially to kidneys and lungs).
Phase under treatment (first years)
Once treatment has started (usually with corticosteroids and possibly other medications), improvement often occurs fairly quickly. This is a crucial moment.
**How symptoms change:**
- **Fatigue and general malaise**: usually decreasing after weeks to months
- **Swellings**: salivary glands and lymph nodes usually shrink
- **Abdominal complaints**: usually reduce significantly, although not always completely
- **Dry eyes**: can improve, but not always completely
- **Blood values**: IgG4 concentration and inflammation markers (CRP, ESR) decrease, although not always to normal
- **Function of affected organs**: can improve, but damaged kidney tissue or scarred lungs do not fully recover
This process can take **3–6 months** to reach full effect. Some achieve remission quickly (virtually no symptoms anymore), others retain some residual complaints.
**What this means for daily life: **
For many people, this feels like "back to normal" — more energy, less pain, better appetite. At the same time, one must adjust to medication schedules, possible side effects of treatment, and regular check-ups. Many patients initially feel better, which helps morale.
**Figures about this phase: **
Approximately **70–80% of patients achieve remission** (disappearance of active symptoms) under initial treatment, usually within 6–12 months (studies from 2020–2025). This depends heavily on which organs are affected: pancreatic disease usually responds better than kidney disease. However, **20–40% experience later return of symptoms** (relapse) within 2–5 years after stopping or reducing medication (source: studies from recent years; individual differences are large).
Phase of remission (long-term management)
Many patients eventually reach a state in which active inflammation is controlled, even though not all symptoms are completely gone. This can last for years.
**What this looks like:**
- **No or minimal active symptoms**: many people feel almost normal, although fatigue may persist
- **Blood values**: stabilize, IgG4 may remain low but does not need to be completely normal
- **Imaging**: tissue remains swollen or scarred visible, but does not grow further
- **Medications**: usually slowly tapered to the lowest effective dose, or sometimes stopped under close monitoring
- **Residual complaints**: approximately half of patients retain some dry eyes, mild fatigue, or fluctuating abdominal complaints
**What this means for daily life: **
Most people can return to normal daily life, work, and hobbies, although some experience persistent fatigue. Regular check-ups (several times a year) are needed to catch relapse early.
**Figures about this phase: **
**Median survival for patients with IgG4-related disease is more than 15–20 years** after diagnosis (based on cohort studies from recent years), but this says nothing about any one person — much depends on which organs are affected and how well they respond to treatment. Mortality is usually not directly from the disease itself, but from complications (e.g., kidney failure, lung fibrosis) if the disease goes unrecognized for a long time, or from side effects of long-term treatment.
Phase of symptom recurrence (relapse)
An important feature of IgG4-related disease is that it can return, even during treatment or after stopping it.
**Complaints that may appear:**
- **Renewed swellings**: of salivary glands, lymph nodes, or both
- **Return of abdominal pain** (sometimes worse than before)
- **New organ involvement**: the disease can spread to other parts of the body
- **Elevation of IgG4 and inflammatory markers** in blood tests
- **Decline in kidney function** or lung involvement
Relapse can occur after stopping treatment (most common), but also sometimes **during ongoing treatment** (treatment-resistant case).
**What this means for daily life: **
Psychologically, a return can be disappointing; practically, it usually means restarting or adjusting medication, and more intensive monitoring.
**Figures about this phase: **
**20–40% of patients who go into remission experience a return of symptoms** within 2–5 years (based on follow-up studies). Risks for relapse depend on background: patients who responded well to initial treatment have relatively lower risk. After a relapse, most people respond again to more intensive or adjusted treatment, although some patients become more difficult to control.
Phase of long-term organ damage
In cases where the disease is not recognised for a long time, or where certain organs become severely damaged, lasting consequences can occur.
**Possible lasting complaints:**
- **Reduced kidney function**: chronic kidney disease (sometimes ending in kidney dialysis, very rare)
- **Lung fibrosis**: lasting shortness of breath after healing from the initial inflammation
- **Narrowing of tubular structures**: in bile ducts (icteric symptoms: jaundice, dark urine) or gastrointestinal tract
- **Persistent dry eyes** and eye problems
- **Neurological consequences** (very rare): residual symptoms after spinal cord inflammation
**What this means for daily life: **
This is fortunately uncommon — most patients recover well. Those with severe kidney damage can live a lifetime with reduced kidney function, but dialysis is rarely needed. Lung patients may thereafter tire more quickly with exertion.
**Figures about this phase: **
**Only 5–10% of well-treated patients undergo serious, permanent organ damage** (population averages). This underscores the importance of early recognition and treatment. Kidney failure occurs in approximately 1–3% of all patients, usually if kidney disease has remained untreated for years.
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When to contact your healthcare provider?
Contact your doctor if you:
- Experience **sudden severe abdominal pain**, with or without vomiting
- **Get a fever** lasting more than a few days, especially in combination with other symptoms
- Notice **yellow skin or eyes** (possible bile duct obstruction)
- Become **severely short of breath**, especially with exertion or at rest
- Have **persistent cough** (more than a few weeks), especially with blood
- Experience **sharp decrease in urination** or visible blood in urine
- Notice **sudden deterioration in vision** or severity of eye pain
- Experience **return of symptoms** after a period of well-being (swelling, abdominal complaints, fatigue)
- Develop **new symptoms**