Oxygen affinity of hemoglobin is increased by all of the following except

Options

A. (a) alkalosis
B. (b) hypoxia
C. (c) increased Hb
D. (d) hypothermia

Answer

To solve the question regarding the factors that affect the oxygen affinity of hemoglobin, we will analyze each option provided and determine which one does not increase this affinity.

### Step-by-Step Solution:

1. **Understanding Oxygen Affinity of Hemoglobin**:
- The oxygen affinity of hemoglobin refers to how readily hemoglobin binds to oxygen. Various physiological factors can influence this affinity.

2. **Reviewing the Options**:
- **Option A: Alkalosis**: Alkalosis is a condition where the pH of the blood increases (becomes more alkaline). According to the Bohr effect, an increase in pH leads to an increased affinity of hemoglobin for oxygen. Thus, this option increases the affinity.

- **Option B: Hypoxia**: Hypoxia refers to a deficiency in the amount of oxygen reaching the tissues. In this condition, the oxygen affinity of hemoglobin is decreased because there is less oxygen available for binding. Therefore, this option does not increase the affinity.

- **Option C: Increased Hemoglobin**: An increase in hemoglobin levels (due to more red blood cells) enhances the oxygen-carrying capacity of the blood. More hemoglobin means a higher potential for oxygen binding, thus increasing the affinity.

- **Option D: Hypothermia**: Hypothermia is a condition where the body temperature drops. Lower temperatures can increase the affinity of hemoglobin for oxygen, as the body tries to maintain homeostasis and ensure adequate oxygen supply to tissues.

3. **Identifying the Exception**:
- After analyzing all options, we find that **Option B: Hypoxia** is the only condition that does not increase the oxygen affinity of hemoglobin. Instead, it decreases it.

### Conclusion:
The answer to the question is **Option B: Hypoxia**.