Hyposmia

Slow-SPEED UK is an 18-month randomised, double-blind feasibility trial evaluating the delivery, adherence, and acceptability of a digitally supported physical activity programme in community-dwelling adults aged 40 and over with objectively confirmed hyposmia (reduced sense of smell) and low baseline physical activity. Participants are randomly assigned 1:1 to either a full-dose activity-support programme (targeting a 100% increase in daily step count) or a very low-dose active control (targeting a 10% increase). Both arms are delivered via a smartphone application linked to a wearable activity monitor (Fitbit Charge 6), with personalised weekly goals expressed as relative percentages to maintain blinding. The study is not designed to test clinical efficacy.

The goal of this clinical trial is to learn if ScentCare, a novel olfactory training device and accompanying companion web-based application, will lead to improved olfactory and well-being outcomes in elderly patients with Olfactory Dysfunction (OD). The main question it aims to answer is: \- What effect does the olfactory training device (ScentCare) and accompanying companion web-based application have on olfaction? Researchers will compare ScentCare to solving Sudoku puzzles to see the effects of olfactory training using this novel device on olfaction. Previous studies have used Sudoku puzzles when studying the effect of smell training. Since smell training is thought to work by stimulating and engaging higher order cognition, Sudoku is a suitable activity for participants in the control group since it serves as a correlate with similar degree of stimulation. Participants will: * Use ScentCare (intervention) or solve Sudoku puzzles (control) twice daily for 3 months. * Visit the clinic twice, once upon enrollment and once three months later. * Complete a formal smell test using Sniffin' Sticks smell test at the beginning of the study and again at the end of the study (3 months) during the initial and follow up visit. * Complete questionnaires at the beginning of the study and again at the end of the study (3 months) during the initial and follow up visit.

The goal of this clinical trial is to determine whether two different delivery methods of autologous platelet-rich plasma (PRP) can improve olfactory function in adults with persistent olfactory dysfunction lasting more than three months. The main questions it aims to answer are: 1. Does carrier-assisted topical application of PRP lead to comparable or better improvement in smell function than intranasal injection of PRP? 2. Which method provides greater patient comfort and fewer adverse effects? Researchers will compare carrier-assisted topical PRP application to intranasal PRP injection to see if one approach is more effective in restoring olfactory function. Participants will: 1. Receive a single PRP treatment delivered either by injection or via a PRP-soaked carrier placed into the olfactory cleft. 2. Continue daily olfactory training for three months following the intervention. 3. Undergo smell testing (Sniffin' Sticks) before and after treatment and complete quality-of-life questionnaires.

* Causes of olfactory dysfunction can be classified into conductive and sensorineural causes. * Conductive causes are mainly due to structural nasal problem, which can be treated by nasal surgery * Sensorineural causes included post-infection, post-head injury, post Head and Neck irradiation and other central nervous system diseases. * Olfactory Training is well established treatment for sensorineural olfactory dysfunction in foreign countries. * Olfactory Training by neurological chemosensory stimulation using aromatic substances delivered via electronic portable aromatic rehabilitation (EPAR) diffuser was proved to be effective treatment in COVID-19 related olfactory dysfunction in recent Hong Kong study. * However, there is a lack of local study on the effect of Olfactory Training in other non-COVID-19 sensorineural causes of olfactory dysfunction in Hong Kong population.

Olfactory dysfunction is a defining symptom of COVID-19 infection. Studies have demonstrated improved olfaction in patients with post infectious olfactory dysfunction after an olfactory training (OT). The aim of this study is to assess the clinical outcomes of olfactory training (12 weeks) therapy in the treatment of persistent olfactory dysfunctions after COVID-19. Specially, we aim to compare the effectiveness of two different olfactory training (different odors). A group will train themselves with 4 scents (rose, orange, clove and eucalyptus) and another group with 4 different scents (cheese, coffee, strawberries and lemon). Olfaction sensory evaluation will be performed by using different olfaction tests (Sniffin' Sticks and UPSIT) and complete questionnaires to assess olfactory perception and particularly parosmia and phantosmia.