Sick Note for Glandular Fever: UK GP Guidelines & Sickness Rights

Sickness absence in the United Kingdom is often triggered by acute painful physical conditions, with glandular fever standing out as a common cause of sudden, significant workplace disruption. Sufferers of glandular fever, also known clinically as infectious mononucleosis or mono, frequently experience a severe sore throat, high fever, swollen lymph nodes, and profound, long-lasting fatigue. For many individuals, the initial response is to try to push through the discomfort, hoping to maintain productivity. However, continuing to work with a painful viral infection like glandular fever can worsen your condition, delay your recovery, and put vulnerable colleagues or customers at risk. It is essential to recognize when a physical boundary has been reached and when taking a period of dedicated rest is the most responsible action for your health.

The evidence needed depends on the length of absence and the recipient's requirements. Ordinary first-week self-certification, a statutory fit note and an agreed private certificate are different routes. This guide considers work effects, reporting and support without assuming that buying evidence guarantees pay or job protection.

For sickness lasting more than seven calendar days, the employer can ask for a fit note or agree suitable alternative evidence. Ask the service responsible for your care about the assessment and tell the employer if evidence is delayed. A private certificate is a separate option only where it meets the recipient's requirement. Medical care should follow the symptoms, not the paperwork timetable.

Symptoms of Glandular Fever

To understand why glandular fever is so debilitating, we must look at the biology of the virus. Glandular fever is caused by the Epstein-Barr virus (EBV), which is a member of the herpes virus family. It is one of the most common human viruses and is spread primarily through saliva, earning it the common nickname of the kissing disease. The virus infects epithelial cells in the throat and then spreads to B lymphocytes, causing them to proliferate and triggering a robust immune response.

The resulting symptoms are highly distinct and can cause severe distress. Sufferers typically experience a high temperature (fever), a very sore throat that is often mistaken for severe tonsillitis, swollen and tender lymph nodes in the neck and armpits, and significant fatigue. The sore throat can be so intense that swallowing liquids or soft food is extremely painful, leading to a risk of dehydration. In addition, the virus can cause inflammation of the liver (mild hepatitis) and enlargement of the spleen (splenomegaly). Spleen enlargement is a critical complication, as it makes the organ fragile and susceptible to rupture from physical impact.

Fatigue can continue after the sore throat or fever improves, and it affects people differently. Describe its effect on daily activities and the job to the treating team. Do not assume that a fixed recovery period or a standard certificate extension applies to everyone.

The Public Health Dimension: Contagiousness and Infection Control

Glandular fever can spread through saliva. Avoid sharing cups or cutlery and follow hygiene advice. Infectiousness can last beyond the point when someone feels better, so a long period of positive symptoms or possible shedding is not itself a fixed exclusion period from every job.

NHS guidance says you can return to work or school as you start to feel better. Discuss persistent fatigue and any strenuous duties with the treating clinician and employer. Avoid heavy lifting and strenuous activity during recovery as advised; do not treat this as a personal clearance to resume demanding tasks.

For employees who work in roles involving close contact with vulnerable individuals, such as healthcare settings, care homes, or schools, taking adequate time off is essential. The physical exhaustion and fatigue can make performing these roles safely impossible. If your absence extends beyond seven days because of glandular fever, obtaining a fit note is necessary to cover the remaining time.

The Sickness Timeline and Statutory Sick Pay for Glandular Fever

If you contract glandular fever, understanding the UK sickness rules is essential. For the first seven calendar days of your absence, you do not need to provide a doctor's fit note. You can self certify by completing your employer's sickness reporting forms or the government's SC2 form. This period of self certification allows you to rest and recover at home without the stress of trying to see a doctor.

If symptoms continue beyond seven days, ask the employer what evidence it requires and the treating service how to arrange a review. The work impact and supported dates depend on the individual assessment. Fatigue may last longer than the initial illness, but it does not set a standard certificate length.

For sickness from 6 April 2026, eligible employees can receive SSP from their first full qualifying day, meaning a day they would normally work. There is no lower earnings limit or three-day waiting period. In 2026/27, the ordinary weekly amount is the lower of £123.25 or 80% of average weekly earnings, for up to 28 weeks. Other eligibility rules and transitional protection can apply. See GOV.UK SSP amounts and our current SSP calculation guide.

A private medical certificate is clinical evidence following an assessment; it is not automatically the same document as a statutory Med3 fit note. An employer may agree to accept appropriate alternative evidence. Confirm the required document before paying, especially for SSP. A GMC registration number or verification code confirms the issuer or authenticity, not guaranteed acceptance or entitlement. See GOV.UK evidence guidance and employer acceptance of private evidence.

How a Doctor Assesses and Diagnoses Glandular Fever

When you consult a doctor to obtain a fit note for glandular fever, they will perform a clinical assessment to evaluate the severity of your symptoms and determine how they impact your ability to work safely. Because the symptoms of glandular fever can overlap with other conditions like streptococcal tonsillitis or cytomegalovirus, a clinical diagnosis is often confirmed with diagnostic tests.

The assessment typically covers several areas:

• Clinical History and Symptom Check: The doctor will review the onset and duration of your symptoms, specifically evaluating the throat infection, fever, swollen lymph nodes, and the level of fatigue.
• Physical Examination: The clinician will examine your throat, palpate the lymph nodes in your neck and armpits, and gently examine your abdomen to check for signs of spleen or liver enlargement.
• Diagnostic Blood Tests: A simple blood test, such as a Monospot test or a full blood count, is often performed. The full blood count can show an elevated number of atypical lymphocytes, which is characteristic of glandular fever. A Monospot test checks for specific antibodies produced in response to EBV.
• Complications Risk: They will assess whether there is a risk of airway obstruction from severely swollen tonsils, or if there are signs of jaundice indicating liver involvement.

Any certificate period depends on assessment and the evidence available. It does not establish that the spleen is normal or clear someone for heavy work or contact sport. Those questions should be discussed with the treating service.

Avoid strenuous activities such as heavy lifting while recovering, following the treating clinician's advice. The date for restarting demanding activity is individual rather than an automatic four-to-six-week rule. Severe abdominal pain, inability to swallow or severe breathing difficulty needs emergency help.

Designing a Phased Return to Work after Glandular Fever

Returning to work after glandular fever requires careful management due to the persistent fatigue that often follows the acute infection. Attempting to return to full-time hours or physically demanding tasks too quickly can lead to a relapse and prolong your recovery. A phased return to work is highly recommended.

Key considerations for a safe return to work include:

• Gradual Increase in Hours: Starting with shorter shifts or working fewer days per week, and slowly increasing your hours over several weeks as your energy levels recover.
• Modification of Duties: Temporary modifications to your job role to avoid heavy lifting or intense physical labor, particularly if you have residual spleen enlargement.
• Regular Breaks: Allowing regular rest periods throughout the working day to manage fatigue and maintain focus.
• Flexible or Remote Working: If your role allows, working from home can save energy by eliminating a commute, allowing you to manage your workload more effectively.

If you struggle to secure a prompt GP appointment to discuss these adjustments, you can explore the fast, secure, and professional private options detailed on our online sick note consultation page to ensure you receive a balanced, timely assessment.

How DoctorCert Supports Glandular Fever Recovery

When you are suffering from the intense sore throat, high fever, and overwhelming fatigue of glandular fever, the last thing you want to do is travel to a GP surgery, sit in a waiting room, and risk spreading the virus to vulnerable patients. Remote clinical support is the safest and most convenient option.

DoctorCert offers an online request for a private medical certificate. Complete the booking questionnaire accurately; a GMC-registered doctor reviews the information and may decline the request or need further information. This is a documentation assessment, not a replacement for examination, tests, treatment or your usual care team. Check the service scope, price and refund policy before booking.

• Explain the symptoms, relevant dates and how they affect your work in the booking questionnaire.
• A GMC-registered doctor reviews the request. Issuance and the dates covered depend on that assessment.
• If approved, the private certificate is sent digitally. Confirm that the recipient accepts this evidence before requesting it.
• If the doctor cannot issue a certificate, the published refund policy applies. Seek appropriate medical care for symptoms.

Before payment, ask the recipient to confirm the document and dates it needs. If it wants a statutory or specialist form, check that the service can provide it rather than assuming that a general private letter is interchangeable.

Frequently Asked Questions

Can I get a sick note for glandular fever online?

Yes. GMC registered doctors can conduct remote clinical assessments based on your symptoms, medical history, and blood test results to issue a valid fit note online, avoiding the need for an in-person GP visit.

How long can you be signed off work with glandular fever?

There is no standard number of days off or certificate length for this condition. The decision depends on symptoms, their effect on the actual job, available evidence and clinical judgement. Recovery estimates describe groups of patients; they are not a personal return date or a promise of the dates a service can certify.

Is glandular fever contagious at work?

Glandular fever is spread through saliva and is not as contagious as the flu. You should avoid close contact, sharing cups, and staying off work during the acute phase when you have a fever. Once the fever is gone, you can return to work if you feel well enough, practicing good hand hygiene.

Can my employer refuse a private glandular fever medical certificate?

A private medical certificate is clinical evidence following an assessment; it is not automatically the same document as a statutory Med3 fit note. An employer may agree to accept appropriate alternative evidence. Confirm the required document before paying, especially for SSP. A GMC registration number or verification code confirms the issuer or authenticity, not guaranteed acceptance or entitlement. See GOV.UK evidence guidance and employer acceptance of private evidence.

Need a medical certificate?

Use accurate dates and describe the symptoms and work effects in your own words. The booking questionnaire is an information-gathering step, not a promise that the reviewing doctor can issue the requested evidence.

Sources and guidance

Guidance checked on 9 October 2026. GOV.UK SSP amounts; GOV.UK sickness evidence.

Explain fatigue and physical duties separately

Describe the difference between feeling better at rest and being able to sustain the actual job. Tell the treating clinician about lifting or strenuous work, as well as fatigue. A private certificate is not clearance for sport or heavy work.

Workplace hygiene and possible ongoing saliva transmission are separate from the individual recovery plan. Follow the treating team's advice without assuming you must be absent for every week the virus might still be present.

• Keep the treating service's activity advice.
• Agree realistic duties and review them if fatigue increases.
• Seek urgent care for serious swallowing, breathing or abdominal symptoms.

Editorial sources and scope

Sources checked on 16 October 2026: NHS guidance.

This article provides general information. It is not an individual clinical assessment or employment-law decision. A private certificate is issued only where the reviewing doctor can support it, and the recipient decides whether it meets the required purpose.

Related guidance

Do I Need a Sick Note for Work?; Request an assessment.