Dr. Gregory Michael Roybal M.D.

IntroductionA dry cough is a type of cough that does not accompany the production of mucus or phlegm. Most cases of dry cough are caused by certain allergic reactions from allergens, such as pollutants, dust, or toxins. The body usually tries to expel these irritants by coughing it out. In some...

Vitamin D, also known as the ‘sunshine vitamin’, is an important nutrient that the human body needs in order to maintain a healthy life – both physically and mentally. Vitamin D serves numerous vital bodily functions, including supporting the immune system, improving muscle function,...

Listeriosis is a foodborne disease caused by the infection of the bacteria Listeria monocytogenes. This infection may cause severe symptoms in pregnant women and people who have a weak immune system. It may also affect newborns and the elderly. The symptoms are generally not very serious in the case...

Swollen feet can be easily linked to pregnancy, standing for long hours, or injury by most people. These cases are often temporary and not a cause for concern. However, swollen feet can also be experienced by people without these factors and can be a sign of an underlying medical condition,...

Croup in AdultsAlthough croup is commonly observed in children who are 6 months to 3 years old, it is also possible for adults to get the infection in rare cases. Croup is a viral respiratory infection caused by human parainfluenza viruses (HPIVs). However, other causes of croup may include...

Primary care providers, family physicians, generalists, and internists can be tricky designations to understand because these healthcare providers similarly cover a number of areas when diagnosing and treating people. However, knowing their differences can be helpful when it comes to finding the...