Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is. However I will try to provide you with some useful information.
Coughing, sneezing, or bending over are maneuvers called valsalva, in which the
pressurePressure ulcer in the
thoracicEchocardiogram
Lung needle biopsy
Thoracic aortic aneurysm
Thoracic ct
Thoracic organs
Thoracic outlet anatomy
Thoracic outlet syndrome
Thoracic spine x-ray
Vertebra, thoracic (mid back) cavity increases as one "bears down". This
pressurePressure ulcer is transmitted to the brain. When headaches occur with valsalva, the concern would be that there is, for whatever reason, an abnormal build up of
pressurePressure ulcer in the
skullCranial ct scan
Malignant otitis externa
Skull
Skull anatomy
Skull of a newborn
Skull of an adult
Skull x-ray. This occurs with various
disordersAdjustment disorder
Anorexia nervosa
Asperger syndrome
Autism
Autoimmune disorders
Bipolar disorder
Bipolar disorder
Bleeding disorders
Borderline personality disorder
Bulimia
Chronic motor tic disorder, the most concerning of which are tumors. Please understand I am not trying to imply that I think you have a tumor, only that it is a concern in someone who has headache with valsalva. Other possibilities include specific brain variations such as Chiari malformation, a specific type of vasospasm in which the blood vessels of the brain narrow with specific types of exertion, leading to headache (what is termed reversible cerebral vasoconstriction), a condition called benign intracranial hypotension, and several other causes, some of which are benign. There may be no associated disorder at all, or it may be non-neurologic, such as musculoskeletal (from neck straining) or from sinus disease.
As you can see there are many potential causes to your symptoms, some of which are more concerning than others. but in general, symptoms such as yours warrant an evaluation, and evaluation by your primary doctor/family physician (internist etc) is recommended; imaging of the brain (with a CT brain or MRI) is important to exclude many of these causes if there is concern for them. If you have already had imaging of the brain, and there were no abnormalities, then the majority of the more serious conditions can be safely excluded.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.