Ties: they're what the majority of the men in the western working world wear day in, day out around their necks. Some wear them way too long. Others wear them comically short. Some have bows, some wear bolos. But one widely-circulating study is making one thing certain: they restrict circulation of blood to your brain.
The study, which appeared in the journal Neuroradiology, took place at the University Hospital Schleswig-Holstein in Germany with 30 participants, half of whom had the blood flow to their heads observed while wearing a tie, while the other half went tie-free. The squeezes the veins to the head, ultimately reducing circulation by 7.5%. You might not be acutely aware of this, but it's a sizable percentage; enough to make a potentially fatal difference if you already have high blood pressure (I did some research on this: you'd have to have REALLY high blood pressure to have a tight tie be the catalyst for your demise).
Wearing a tie can also add unneeded pressure to your eyes, which could lead to an early onset of glaucoma. And if you're still of the mindset that wearing a tie makes a difference in professionalism: according to a 2015 study, it only really makes a difference to the person wearing the tie.