Traveller's diarrhoea is common. But it is difficult to put a percentage on it as a lot depends on lots of different factors. However, we do know that traveller's diarrhoea can be serious and can cause complications - from lactose intolerance to irritable bowl syndrome.

To find out more, please have a listen to this podcast with Daniel Leung, Professor at the Division of Infectious Diseases, Dr Thomas D. Rees and Natalie B. Rees Presidential Endowed Chair in Global Medicine University of Utah School of Medicine.

For more on traveller's diarrhoea, visit BMJ Best Practice.

Competing interests: DTL receives authorship royalties from UpToDate, Inc, for a chapter on travel medicine; is an author of upcoming chapters on traveller's diarrhoea for the US CDC Yellow Book; is the past president of the American Committee on Clinical Tropical Medicine and Travelers' Health - Clinical Group within the American Society of Tropical Medicine and Hygiene; and is an author of some of the references cited in this topic.

Pulmonary embolism is common and important. So it is vital that we get the diagnosis and management of this condition right.

To find out more about this condition, please do listen to this BMJ Best Practice podcast interview with Scott Woller, Director of the Thrombosis Clinic, Intermountain Medical Center and Professor of Medicine at the University of Utah.

For more on pulmonary embolism, visit BMJ Best Practice.

Competing interests: SCW declares that he is expecting to receive funding of an investigator initiated grant from Janssen Pharmaceuticals to Intermountain Health - with no direct compensation to himself.

Migraine is very common, affecting an estimated 1.16 billion people worldwide.

It is one of the most disabling neurological disorders. So it is vital that we get diagnosis, management and prevention of this condition right.

To find out how to do this, please listen to this BMJ Best Practice podcast with Timothy Collins, Associate Professor of Neurology and Chief of the Headache Division, Department of Neurology, Duke University Medical Center.

For more on migraine, visit BMJ Best Practice.

Competing interests: TAC provides expert testimony for legal cases regarding headache disorders and treatment (approximately one or two cases per year). TAC is an author of several references cited in the BMJ Best Practice topic on migraine.

Comorbidities are common and important and have a massive impact on the delivery of care.

The BMJ Best Practice Comorbidities Manager is designed to help healthcare professionals deliver better care for patients with multiple illnesses.

To find out more, please do listen to this podcast with Dr Preethi Pirlamarla, Advanced Heart Failure and Transplant Cardiologist at the University of Washington.

Competing interests: PP is a member of the BMJ Best Practice Comorbidities Manager panel. 

Mumps used to be a common childhood disease. Then it became a lot less common because of vaccination. But now unfortunately it is becoming more common again.

So it is vital that we get the diagnosis, management and prevention of this condition right.

To find out more about this condition, please do listen to this BMJ Best Practice podcast interview with Dr Kristine Macartney, Director of the National Centre for Immunisation Research and Surveillance, Australia.

For more on mumps, visit BMJ Best Practice.

Competing interests: none 

Pertussis or whooping cough is an acute infectious disease caused by Bordetella pertussis. It is highly contagious, highly serious, and highly preventable.

To find out more about this condition, please do listen to this BMJ Best Practice podcast interview with Professor Sir Andrew Pollard, Director of the Oxford Vaccine Group and Ashall Professor of Infection and Immunity in Oxford.

Competing interests: AP has been chair of JCVI for the past 12 years.

For more on pertussis, visit BMJ Best Practice.

Social anxiety disorder is common. The 1-year point prevalence rate is about 7% and the estimated lifetime prevalence about 12%.

And social anxiety disorder can have a real effect on a patient’s life.

To find out more about this condition, please do listen to this BMJ Best Practice podcast interview with Professor Craig Sawchuk of the Department of Psychiatry and Psychology, Mayo Clinic.

Craig is also the author of our BMJ Best Practice topic on this subject.

For more on social anxiety disorder, visit BMJ Best Practice.

Competing interests: None