I thought sharing this great list about the physical signs of aging.
1. Muscle mass decreases. (muscle/weight/height Body Mass Index Increases)
2. Fat increases as a percentage of body weight.
3. Strength, energy and speed of the body decreases.
4. Base Metabolic Rate (metabolism) decreases.
5. Aerobic Capacity, the capacity to process oxygen, decreases. Red blood cells as a percentage of total blood volume (hematocrit) decreases until the average at age 90 is what is considered to be "anemia" at age 40.
6. Body cells become resistant to insulin.
7. LDL Cholesterol ("bad" cholesterol) and triglicerides increase, and HDL Cholesterol ("good" cholesterol) falls.
8. Blood pressure increases.
9. Bone mineral density decreases.
10. Density of calcium in circulatory system increases.
11. Kidney functions decrease.
12. We lose neurons in our brain. This leads to Alzheimer's, Parkinson's, and Senile Dementia.
13. The vagus nerve, the longest nerve in our body, deteriorates... and all the nervous system surely also deteriorates.
14. Growth Hormone secretion drops.
15. Testosterone in men, and estrogen and progesterone in women, drops.
16. Sexual desire drops.
17. Thyroid (a hormone which affects metabolism) drops.
18. melatonine (a hormone which regulates the body clock) drops.
19. DHEA (a hormone precursor to testosterone and estrogen) drops.
20. EPO, (erythropoyetin, a hormone which stimulates the production of new red blood cells) drops.
21. Estradiol, a female hormone, increases in men.
22. Cortisol, "the Death Hormone," increases.
23. Good enzymes (Super Oxidase Dimutase, etc.) drop.
24. A bad enzyme, MAO-B increase in the brain. MAO-B destroys neurons that produce dopamine, which is a neuro-transmitter.
25. Aromatase enzyme, a bad enzyme, increases. Aromatase converts testosterone to estrogen in men, which deprives him of libido.
26. The thickness of skin decreases, resulting in more wrinkles.
27. Prolactin, a female hormone, increases in the body of a male, presumably depriving him of some sexual libido.
28. Water proportion in the body and in the skin, drops. This results (among other things) in dryer skin, and more wrinkles.
29. Sense of hearing drops.
30. Sense of taste drops... "everything tastes the same"
31. Sense of vision, especially capacity to read small letters in low light, decreases.
32. Hair falls and loses its color (it becomes white).
33. The thymus gland, the master of the immune system, shrinks and atrophys, thus lessening our immune system.
34. Our liver, brain, and other critical organs shrink in size, thus affecting their functions.
35. Lipofuscine ("liver spots") accumulates in our hands and our brains. This snuffs out many neurons in our brain.
36. The circulatory system deteriorates in length and width.
37. The velocity of blood flow decreases.
38. Inflammation increases in our body.
39. "Deep sleep" becomes more scarce and less profound.
40. Digestion becomes slower and less complete.
41. The retina of the eye becomes thinner, in many cases detaching.
42. The macula of the eye loses some of its shape after age 40, and causes distorted vision.
43. Micro-vessels in the eye pop, covering the retina, causing partial loss of vision, or complete blindness.
44. Night-vision decreases.
45. Melanocytes continually release small amounts of the brown- black pigment called melanin into the skin. Exposure to sunlight signals the melanocytes to produce more melanin. Melanin determines our normal skin color and attempts to protect our skin from severe sun damage. As we age, our melanocytes begin to function less effectively. The density of active melanocytes in the skin is reduced by 10% to 20% every 10 years, starting in our late 30's and 40's. Melanocytes are also responsible for hair color, so their loss explains why 50% of people are gray by age 50.
Source:
http://www.rajeun.net/signs.html
