A panic attack is a sudden onset of acute anxiety that is often mistaken for a life-threatening illness, and for those who suffer from recurrent attacks it can often be debilitating. Physical symptoms of an attack can include rapid heart rate, dizziness, shaking, nausea, abdominal cramping, numbness of the hands and feet, chest pain and shortness of breath. Many people report feeling like they were going to die during these episodes, which can last for several minutes.
About 23% of Americans report having experienced a panic attack while up to 4.7% of Americans  with recurrent attacks have been diagnosed with panic disorder. Women are twice as likely as men to develop the condition.
Panic disorder is complex involving psychological, neuro-biological and environmental factors. Neuroimaging studies  have highlighted the role of the amygdala in panic disorder but also implicate the “thalamus, hypothalamus, and brain stem regions including the periaqueductal gray, parabrachial nucleus, and locus ceruleus."
Environmental and psychological components engaging the sympathetic nervous system and a fight-flight response in the disorder include chronic or acute stress, trauma, excess caffeine or alcohol intake. Stress-induced dysfunction of the HPA axis can affect the balance of steroid hormones, adrenaline and cortisol, and may contribute to the condition.
Left unaddressed, recurrent panic attacks may lead to phobias, depression, substance misuse and abuse.
Panic attacks can be aborted using sedative drugs, but there is no effective drug treatment for the underlying disorder. In one long-term study on the use of psychodynamic psychotherapy and cognitive behavioural therapy for panic attacks over 2 years, the condition improved in 70% of patients.  Acupuncture has also been shown to be effective in reducing anxiety.
Myopia, also known as nearsightedness, is a common cause of blurred vision that typically begins in childhood. An estimated 30% of Americans have myopia but this number is increasing.
Myopia is caused by a lengthening of the eyeball. The lens and cornea can also become unevenly or too curved, and this distorts light rays as they travel through the eyes, which is called refraction. This leads “the refractive image formed by the cornea and the lens to fall in front of the photoreceptors of the retina.”
According to Yale University researchers, the bacterium causing Lyme disease has circulated in the forests of North America for 60,000 years. Carried by ticks, the bacterium Borrelia burgdorferi had been limited primarily to deer as their animal host. However, with forest fragmentation and a surge in the deer population, the ticks have multiplied, carrying the infection to other mammals including humans.
Lyme disease came to public attention suddenly in the 1970s when a group of children in Lyme, Connecticut, began exhibiting odd symptoms – bull’s eye shaped rashes, swollen knees, partial paralysis, headaches, and fatigue.